@article{VeldhoenBehzadiLenzetal.2017, author = {Veldhoen, Simon and Behzadi, Cyrus and Lenz, Alexander and Henes, Frank Oliver and Rybczynski, Meike and von Kodolitsch, Yskert and Bley, Thorsten Alexander and Adam, Gerhard and Bannas, Peter}, title = {Non-contrast MR angiography at 1.5 Tesla for aortic monitoring in Marfan patients after aortic root surgery}, series = {Journal of Cardiovascular Magnetic Resonance}, volume = {19}, journal = {Journal of Cardiovascular Magnetic Resonance}, number = {82}, doi = {10.1186/s12968-017-0394-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158693}, year = {2017}, abstract = {Background: Contrast-enhanced cardiovascular magnetic resonance angiography (CE-CMRA) is the established imaging modality for patients with Marfan syndrome requiring life-long annual aortic imaging before and after aortic root replacement. Contrast-free CMRA techniques avoiding side-effects of contrast media are highly desirable for serial imaging but have not been evaluated in the postoperative setup of Marfan patients. The purpose of this study was to assess the feasibility of non-contrast balanced steady-state free precession (bSSFP) magnetic resonance imaging for aortic monitoring of postoperative patients with Marfan syndrome. Methods: Sixty-four adult Marfan patients after aortic root replacement were prospectively included. Fourteen patients (22\%) had a residual aortic dissection after surgical treatment of type A dissection. bSSFP imaging and CE-CMRA were performed at 1.5 Tesla. Two radiologists evaluated the images regarding image quality (1 = poor, 4 = excellent), artifacts (1 = severe, 4 = none) and aortic pathologies. Readers measured the aortic diameters at defined levels in both techniques. Statistics included observer agreement for image scoring and diameter measurements and ROC analyses for comparison of the diagnostic performance of bSSFP and CE-CMRA. Results: Both readers observed no significant differences in image quality between bSSFP and CE-CMRA and found a median image quality score of 4 for both techniques (all p > .05). No significant differences were found regarding the frequency of image artifacts in both sequences (all p > .05). Sensitivity and specificity for detection of aortic dissections was 100\% for both readers and techniques. Compared to bSSFP imaging, CE-CMRA resulted in higher diameters (mean bias, 0.9 mm; p < .05). The inter-observer biases of diameter measurements were not significantly different (all p > .05), except for the distal graft anastomosis (p = .001). Using both techniques, the readers correctly identified a graft suture dehiscence with aneurysm formation requiring surgery. Conclusion: Unenhanced bSSFP CMR imaging allows for riskless aortic monitoring with high diagnostic accuracy in Marfan patients after aortic root surgery.}, language = {en} } @article{VargasCasanovaRodriguezGuerraUmanaPerezetal.2017, author = {Vargas Casanova, Yerly and Rodr{\´i}guez Guerra, Jorge Antonio and Uma{\~n}a P{\´e}rez, Yadi Adriana and Leal Castro, Aura Luc{\´i}a and Almanzar Reina, Giovanni and Garc{\´i}a Casta{\~n}eda, Javier Eduardo and Rivera Monroy, Zuly Jenny}, title = {Antibacterial synthetic peptides derived from bovine lactoferricin exhibit cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines}, series = {Molecules}, volume = {22}, journal = {Molecules}, number = {10}, doi = {10.3390/molecules22101641}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173887}, year = {2017}, abstract = {Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against E. coli (ATCC 11775 and 25922) and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR)\(_2\)K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.}, language = {en} } @article{VangeelPishvaHompesetal.2017, author = {Vangeel, Elise Beau and Pishva, Ehsan and Hompes, Titia and van den Hove, Daniel and Lambrechts, Diether and Allegaert, Karel and Freson, Kathleen and Izzi, Benedetta and Claes, Stephan}, title = {Newborn genome-wide DNA methylation in association with pregnancy anxiety reveals a potential role for \(GABBR1\)}, series = {Clinical Epigenetics}, volume = {9}, journal = {Clinical Epigenetics}, doi = {10.1186/s13148-017-0408-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173825}, year = {2017}, abstract = {Background: There is increasing evidence for the role of prenatal stress in shaping offspring DNA methylation and disease susceptibility. In the current study, we aimed to identify genes and pathways associated with pregnancy anxiety using a genome-wide DNA methylation approach. Methods: We selected 22 versus 23 newborns from our Prenatal Early Life Stress (PELS) cohort, exposed to the lowest or highest degree of maternal pregnancy anxiety, respectively. Cord blood genome-wide DNA methylation was assayed using the HumanMethylation450 BeadChip (HM450, n = 45) and candidate gene methylation using EpiTYPER (n = 80). Cortisol levels were measured at 2, 4, and 12 months of age to test infant stress system (re)activity. Results: Data showed ten differentially methylated regions (DMR) when comparing newborns exposed to low versus high pregnancy anxiety scores. We validated a top DMR in the GABA-B receptor subunit 1 gene (GABBR1) revealing the association with pregnancy anxiety particularly in male newborns (most significant CpG Pearson R = 0.517, p = 0.002; average methylation Pearson R = 0.332, p = 0.039). Cord blood GABBR1 methylation was associated with infant cortisol levels in response to a routine vaccination at 4 months old. Conclusions: In conclusion, our results show that pregnancy anxiety is associated with differential DNA methylation patterns in newborns and that our candidate gene GABBR1 is associated with infant hypothalamic-pituitary-adrenal axis response to a stressor. Our findings reveal a potential role for GABBR1 methylation in association with stress and provide grounds for further research.}, language = {en} } @article{VanSteenbergenBalteauGinionetal.2017, author = {Van Steenbergen, Anne and Balteau, Magali and Ginion, Audrey and Fert{\´e}, Laura and Battault, Sylvain and de Meester de Ravenstein, Christophe and Balligand, Jean-Luc and Daskalopoulos, Evangelos-Panagiotis and Gilon, Patrick and Despa, Florin and Despa, Sanda and Vanoverschelde, Jean-Louis and Horman, Sandrine and Koepsell, Hermann and Berry, Gerard and Hue, Louis and Bertrand, Luc and Beauloye, Christophe}, title = {Sodium-myoinositol cotransporter-1, SMIT1, mediates the production of reactive oxygen species induced by hyperglycemia in the heart}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, doi = {10.1038/srep41166}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-180891}, pages = {14}, year = {2017}, abstract = {Hyperglycemia (HG) stimulates the production of reactive oxygen species in the heart through activation of NADPH oxidase 2 (NOX2). This production is independent of glucose metabolism but requires sodium/glucose cotransporters (SGLT). Seven SGLT isoforms (SGLT1 to 6 and sodium-myoinositol cotransporter-1, SMIT1) are known, although their expression and function in the heart remain elusive. We investigated these 7 isoforms and found that only SGLT1 and SMIT1 were expressed in mouse, rat and human hearts. In cardiomyocytes, galactose (transported through SGLT1) did not activate NOX2. Accordingly, SGLT1 deficiency did not prevent HG-induced NOX2 activation, ruling it out in the cellular response to HG. In contrast, myo-inositol (transported through SMIT1) reproduced the toxic effects of HG. SMIT1 overexpression exacerbated glucotoxicity and sensitized cardiomyocytes to HG, whereas its deletion prevented HG-induced NOX2 activation. In conclusion, our results show that heart SMIT1 senses HG and triggers NOX2 activation. This could participate in the redox signaling in hyperglycemic heart and contribute to the pathophysiology of diabetic cardiomyopathy.}, language = {en} } @article{UriWernerLuehderetal.2017, author = {Uri, Anna and Werner, Sandra and L{\"u}hder, Fred and H{\"u}nig, Thomas and Kerkau, Thomas and Beyersdorf, Niklas}, title = {Protection of mice from acute graft-versus-host disease requires CD28 co-stimulation on donor CD4\(^{+}\) Foxp3\(^{+}\) regulatory T Cells}, series = {Frontiers in Immunology}, volume = {8}, journal = {Frontiers in Immunology}, number = {721}, doi = {10.3389/fimmu.2017.00721}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158469}, year = {2017}, abstract = {Acute graft-versus-host disease (aGvHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell plus T cell transplantation (allo-HSCT). In this study, we investigated the requirement for CD28 co-stimulation of donor CD4\(^{+}\) conventional (CD4\(^{+}\)CD25\(^{-}\)Foxp3\(^{-}\), Tconv) and regulatory (CD4\(^{+}\)CD25\(^{+}\)Foxp3\(^{+}\), Treg) T cells in aGvHD using tamoxifen-inducible CD28 knockout (iCD28KO) or wild-type (wt) littermates as donors of CD4\(^{+}\) Tconv and Treg. In the highly inflammatory C57BL/6 into BALB/c allo-HSCT transplantation model, CD28 depletion on donor CD4\(^{+}\) Tconv reduced clinical signs of aGvHD, but did not significantly prolong survival of the recipient mice. Selective depletion of CD28 on donor Treg did not abrogate protection of recipient mice from aGvHD until about day 20 after allo-HSCT. Later, however, the pool of CD28-depleted Treg drastically declined as compared to wt Treg. Consequently, only wt, but not CD28-deficient, Treg were able to continuously suppress aGvHD and induce long-term survival of the recipient mice. To our knowledge, this is the first study that specifically evaluates the impact of CD28 expression on donor Treg in aGvHD. Moreover, the delayed kinetics of aGvHD lethality after transplantation of iCD28KO Treg provides a novel animal model for similar disease courses found in patients after allo-HSCT.}, language = {en} } @article{UllmannBanksSchmittetal.2017, author = {Ullmann, Tobias and Banks, Sarah N. and Schmitt, Andreas and Jagdhuber, Thomas}, title = {Scattering characteristics of X-, C- and L-Band PolSAR data examined for the tundra environment of the Tuktoyaktuk Peninsula, Canada}, series = {Applied Sciences}, volume = {7}, journal = {Applied Sciences}, number = {6}, doi = {10.3390/app7060595}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158362}, pages = {595}, year = {2017}, abstract = {In this study, polarimetric Synthetic Aperture Radar (PolSAR) data at X-, C- and L-Bands, acquired by the satellites: TerraSAR-X (2011), Radarsat-2 (2011), ALOS (2010) and ALOS-2 (2016), were used to characterize the tundra land cover of a test site located close to the town of Tuktoyaktuk, NWT, Canada. Using available in situ ground data collected in 2010 and 2012, we investigate PolSAR scattering characteristics of common tundra land cover classes at X-, C- and L-Bands. Several decomposition features of quad-, co-, and cross-polarized data were compared, the correlation between them was investigated, and the class separability offered by their different feature spaces was analyzed. Certain PolSAR features at each wavelength were sensitive to the land cover and exhibited distinct scattering characteristics. Use of shorter wavelength imagery (X and C) was beneficial for the characterization of wetland and tundra vegetation, while L-Band data highlighted differences of the bare ground classes better. The Kennaugh Matrix decomposition applied in this study provided a unified framework to store, process, and analyze all data consistently, and the matrix offered a favorable feature space for class separation. Of all elements of the quad-polarized Kennaugh Matrix, the intensity based elements K0, K1, K2, K3 and K4 were found to be most valuable for class discrimination. These elements contributed to better class separation as indicated by an increase of the separability metrics squared Jefferys Matusita Distance and Transformed Divergence. The increase in separability was up to 57\% for Radarsat-2 and up to 18\% for ALOS-2 data.}, language = {en} } @article{TymoshenkoOnykiienkoMuelleretal.2017, author = {Tymoshenko, Y. V. and Onykiienko, Y. A. and M{\"u}ller, T. and Thomale, R. and Rachel, S. and Cameron, A. S. and Portnichenko, P. Y. and Efremov, D. V. and Tsurkan, V. and Abernathy, D. L. and Ollivier, J. and Schneidewind, A. and Piovano, A. and Felea, V. and Loidl, A. and Inosov, D. S.}, title = {Pseudo-Goldstone magnons in the frustrated \(S=3/2\) Heisenberg helimagnet \(ZnCr_2Se_4\) with a pyrochlore magnetic sublattice}, series = {Physical Review X}, volume = {7}, journal = {Physical Review X}, number = {4}, doi = {10.1103/PhysRevX.7.041049}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172770}, year = {2017}, abstract = {Low-energy spin excitations in any long-range ordered magnetic system in the absence of magnetocrystalline anisotropy are gapless Goldstone modes emanating from the ordering wave vectors. In helimagnets, these modes hybridize into the so-called helimagnon excitations. Here we employ neutron spectroscopy supported by theoretical calculations to investigate the magnetic excitation spectrum of the isotropic Heisenberg helimagnet \({ZnCr_2Se_4}\) with a cubic spinel structure, in which spin\(-3/2\) magnetic \({Cr^{3+}}\) ions are arranged in a geometrically frustrated pyrochlore sublattice. Apart from the conventional Goldstone mode emanating from the \((0~ 0~ {q_h})\) ordering vector, low-energy magnetic excitations in the single-domain proper-screw spiral phase show soft helimagnon modes with a small energy gap of \({∼0.17~ meV}\), emerging from two orthogonal wave vectors \(({q_h}~ 0~ 0)\) and \({(0~ {q_h}~ 0)}\) where no magnetic Bragg peaks are present. We term them pseudo-Goldstone magnons, as they appear gapless within linear spinwave theory and only acquire a finite gap due to higher-order quantum-fluctuation corrections. Our results are likely universal for a broad class of symmetric helimagnets, opening up a new way of studying weak magnon-magnon interactions with accessible spectroscopic methods.}, language = {en} } @article{TuanScharfŽutičetal.2017, author = {Tuan, Dinh Van and Scharf, Benedikt and Žutič, Igor and Dery, Hanan}, title = {Marrying excitons and plasmons in monolayer transition-metal dichalcogenides}, series = {Physical Review X}, volume = {7}, journal = {Physical Review X}, number = {4}, doi = {10.1103/PhysRevX.7.041040}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173030}, year = {2017}, abstract = {Just as photons are the quanta of light, plasmons are the quanta of orchestrated charge-density oscillations in conducting media. Plasmon phenomena in normal metals, superconductors, and doped semiconductors are often driven by long-wavelength Coulomb interactions. However, in crystals whose Fermi surface is comprised of disconnected pockets in the Brillouin zone, collective electron excitations can also attain a shortwave component when electrons transition between these pockets. In this work, we show that the band structure of monolayer transition-metal dichalcogenides gives rise to an intriguing mechanism through which shortwave plasmons are paired up with excitons. The coupling elucidates the origin for the optical sideband that is observed repeatedly in monolayers of WSe\(_2\) and WS\(_2\) but not understood. The theory makes it clear why exciton-plasmon coupling has the right conditions to manifest itself distinctly only in the optical spectra of electron-doped tungsten-based monolayers.}, language = {en} } @article{TsonevaMinevFrentzenetal.2017, author = {Tsoneva, Desislava and Minev, Boris and Frentzen, Alexa and Zhang, Qian and Wege, Anja K. and Szalay, Aladar A.}, title = {Humanized Mice with Subcutaneous Human Solid Tumors for Immune Response Analysis of Vaccinia Virus-Mediated Oncolysis}, series = {Molecular Therapy Oncolytics}, volume = {5}, journal = {Molecular Therapy Oncolytics}, doi = {10.1016/j.omto.2017.03.001}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170786}, pages = {41-61}, year = {2017}, abstract = {Oncolytic vaccinia virus (VACV) therapy is an alternative cancer treatment modality that mediates targeted tumor destruction through a tumor-selective replication and an induction of anti-tumor immunity. We developed a humanized tumor mouse model with subcutaneous human tumors to analyze the interactions of VACV with the developing tumors and human immune system. A successful systemic reconstitution with human immune cells including functional T cells as well as development of tumors infiltrated with human T and natural killer (NK) cells was observed. We also demonstrated successful in vivo colonization of such tumors with systemically administered VACVs. Further, a new recombinant GLV-1h376 VACV encoding for a secreted human CTLA4-blocking single-chain antibody (CTLA4 scAb) was tested. Surprisingly, although proving CTLA4 scAb's in vitro binding ability and functionality in cell culture, beside the significant increase of CD56\(^{bright}\) NK cell subset, GLV-1h376 was not able to increase cytotoxic T or overall NK cell levels at the tumor site. Importantly, the virus-encoded β-glucuronidase as a measure of viral titer and CTLA4 scAb amount was demonstrated. Therefore, studies in our "patient-like" humanized tumor mouse model allow the exploration of newly designed therapy strategies considering the complex relationships between the developing tumor, the oncolytic virus, and the human immune system.}, language = {en} } @article{TshitengeFeineisMudogoetal.2017, author = {Tshitenge, Dieudonn{\´e} Tshitenge and Feineis, Doris and Mudogo, Virima and Kaiser, Marcel and Brun, Reto and Bringmann, Gerhard}, title = {Antiplasmodial Ealapasamines A-C,'Mixed' Naphthylisoquinoline Dimers from the Central African Liana Ancistrocladus ealaensis}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, number = {5767}, doi = {10.1038/s41598-017-05719-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170645}, year = {2017}, abstract = {Three unusual heterodimeric naphthylisoquinoline alkaloids, named ealapasamines A-C (1-3), were isolated from the leaves of the tropical plant Ancistrocladus ealaensis J. L{\´e}onard. These 'mixed', constitutionally unsymmetric dimers are the first stereochemically fully assigned cross-coupling products of a 5,8′- and a 7,8′-coupled naphthylisoquinoline linked via C-6′ in both naphthalene portions. So far, only two other West and Central Ancistrocladus species were known to produce dimers with a central 6,6″-axis, yet, in contrast to the ealapasamines, usually consisting of two 5,8′-coupled monomers, like e.g., in michellamine B. The new dimers 1-3 contain six elements of chirality, four stereogenic centers and the two outer axes, while the central biaryl axis is configurationally unstable. The elucidation of the complete stereostructures of the ealapasamines was achieved by the interplay of spectroscopic methods including HRESIMS, 1D and 2D NMR (in particular ROESY measurements), in combination with chemical (oxidative degradation) and chiroptical (electronic circular dichroism) investigations. The ealapasamines A-C display high antiplasmodial activities with excellent half-maximum inhibition concentration values in the low nanomolar range.}, language = {en} }