@article{delAlamoLiMunketal.2020, author = {del Alamo, Miguel and Li, Housen and Munk, Axel and Werner, Frank}, title = {Variational Multiscale Nonparametric Regression: Algorithms and Implementation}, series = {Algorithms}, volume = {13}, journal = {Algorithms}, number = {11}, issn = {1999-4893}, doi = {10.3390/a13110296}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219332}, year = {2020}, abstract = {Many modern statistically efficient methods come with tremendous computational challenges, often leading to large-scale optimisation problems. In this work, we examine such computational issues for recently developed estimation methods in nonparametric regression with a specific view on image denoising. We consider in particular certain variational multiscale estimators which are statistically optimal in minimax sense, yet computationally intensive. Such an estimator is computed as the minimiser of a smoothness functional (e.g., TV norm) over the class of all estimators such that none of its coefficients with respect to a given multiscale dictionary is statistically significant. The so obtained multiscale Nemirowski-Dantzig estimator (MIND) can incorporate any convex smoothness functional and combine it with a proper dictionary including wavelets, curvelets and shearlets. The computation of MIND in general requires to solve a high-dimensional constrained convex optimisation problem with a specific structure of the constraints induced by the statistical multiscale testing criterion. To solve this explicitly, we discuss three different algorithmic approaches: the Chambolle-Pock, ADMM and semismooth Newton algorithms. Algorithmic details and an explicit implementation is presented and the solutions are then compared numerically in a simulation study and on various test images. We thereby recommend the Chambolle-Pock algorithm in most cases for its fast convergence. We stress that our analysis can also be transferred to signal recovery and other denoising problems to recover more general objects whenever it is possible to borrow statistical strength from data patches of similar object structure.}, language = {en} } @article{StrengGroteCarretal.2013, author = {Streng, Andrea and Grote, Veit and Carr, David and Hagemann, Christine and Liese, Johannes G.}, title = {Varicella routine vaccination and the effects on varicella epidemiology - results from the Bavarian Varicella Surveillance Project (BaVariPro), 2006-2011}, series = {BMC Infectious Diseases}, journal = {BMC Infectious Diseases}, doi = {10.1186/1471-2334-13-303}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96297}, year = {2013}, abstract = {Background In 2004, routine varicella vaccination was recommended in Germany for children 11-14 months of age with one dose, and since 2009, with a second dose at 15-23 months of age. The effects on varicella epidemiology were investigated. Methods Data on varicella vaccinations, cases and complications were collected from annual parent surveys (2006-2011), monthly paediatric practice surveillance (Oct 2006 - Sep 2011; five varicella seasons) and paediatric hospital databases (2005-2009) in the area of Munich (about 238,000 paediatric inhabitants); annual incidences of cases and hospitalisations were estimated. Results Varicella vaccination coverage (1st dose) in children 18-36 months of age increased in two steps (38\%, 51\%, 53\%, 53\%, 66\% and 68\%); second-dose coverage reached 59\% in the 2011 survey. A monthly mean of 82 (62\%) practices participated; they applied a total of 50,059 first-dose and 40,541 second-dose varicella vaccinations, with preferential use of combined MMR-varicella vaccine after recommendation of two doses, and reported a total of 16,054 varicella cases <17 years of age. The mean number of cases decreased by 67\% in two steps, from 6.6 (95\%CI 6.1-7.0) per 1,000 patient contacts in season 2006/07 to 4.2 (95\%CI 3.9-4.6) in 2007/08 and 4.0 (95\%CI 3.6-4.3) in 2008/09, and further to 2.3 (95\%CI 2.0-2.6) in 2009/10 and 2.2 (95\%CI 1.9-2.5) in 2010/11. The decrease occurred in all paediatric age groups, indicating herd protection effects. Incidence of varicella was estimated as 78/1,000 children <17 years of age in 2006/07, and 19/1,000 in 2010/11. Vaccinated cases increased from 0.3 (95\%0.2-0.3) per 1,000 patient contacts in 2006/07 to 0.4 (95\%CI 0.3-0.5) until 2008/09 and decreased to 0.2 (95\%CI 0.2-0.3) until 2010/11. The practices treated a total of 134 complicated cases, mainly with skin complications. The paediatric hospitals recorded a total of 178 varicella patients, including 40 (22.5\%) with neurological complications and one (0.6\%) fatality due to varicella pneumonia. Incidence of hospitalisations decreased from 7.6 per 100,000 children <17 years of age in 2005 to 4.3 in 2009, and from 21.0 to 4.7 in children <5 years of age. Conclusions Overall, the results show increasing acceptance and a strong impact of the varicella vaccination program, even with still suboptimal vaccination coverage.}, language = {en} } @article{WiegeringSchickBeeretal.2011, author = {Wiegering, Verena and Schick, Judith and Beer, Meinrad and Gattenl{\"o}hner, Stefan and Girschick, Hermann and Liese, Johannes and Schlegel, Paul and Eyrich, Matthias}, title = {Varicella-zoster virus infections in immunocompromised patients - a single centre 6-years analysis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68723}, year = {2011}, abstract = {Background: Infection with varicella-zoster virus (VZV) contemporaneously with malignant disease or immunosuppression represents a particular challenge and requires individualized decisions and treatment. Although the increasing use of varicella-vaccines in the general population and rapid initiation of VZVimmunoglobulins and acyclovir in case of exposure has been beneficial for some patients, immunocompromised individuals are still at risk for unfavourable courses. Methods: In this single center, 6-year analysis we review incidence, hospitalization and complication rates of VZVinfections in our center and compare them to published data. Furthermore, we report three instructive cases. Results: Hospitalization rate of referred children with VZV-infections was 45\%, among these 17\% with malignancies and 9\% under immunosuppressive therapy. Rate of complications was not elevated in these two high-risk cohorts, but one ALL-patient died due to VZV-related complications. We report one 4-year old boy with initial diagnosis of acute lymphoblastic leukemia who showed a rapidly fatal outcome of his simultaneous varicella-infection, one 1.8-year old boy with an identical situation but a mild course of his disease, and an 8.5-year old boy with a steroiddependent nephrotic syndrome. This boy developed severe hepatic involvement during his varicella-infection but responded to immediate withdrawl of steroids and administration of acyclovir plus single-dose cidofovir after nonresponse to acyclovir after 48 h. Conclusion: Our data show that patients with malignant diseases or immunosuppressive therapy should be hospitalized and treated immediately with antiviral agents. Despite these measures the course of VZV-infections can be highly variable in these patients. We discuss aids to individual decision-making for these difficult situations.}, subject = {Varizellen-Virus}, language = {en} } @article{RosalesAlvarezRettkowskiHermanetal.2023, author = {Rosales-Alvarez, Reyna Edith and Rettkowski, Jasmin and Herman, Josip Stefan and Dumbović, Gabrijela and Cabezas-Wallscheid, Nina and Gr{\"u}n, Dominic}, title = {VarID2 quantifies gene expression noise dynamics and unveils functional heterogeneity of ageing hematopoietic stem cells}, series = {Genome Biology}, volume = {24}, journal = {Genome Biology}, doi = {10.1186/s13059-023-02974-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-358042}, year = {2023}, abstract = {Variability of gene expression due to stochasticity of transcription or variation of extrinsic signals, termed biological noise, is a potential driving force of cellular differentiation. Utilizing single-cell RNA-sequencing, we develop VarID2 for the quantification of biological noise at single-cell resolution. VarID2 reveals enhanced nuclear versus cytoplasmic noise, and distinct regulatory modes stratified by correlation between noise, expression, and chromatin accessibility. Noise levels are minimal in murine hematopoietic stem cells (HSCs) and increase during differentiation and ageing. Differential noise identifies myeloid-biased Dlk1+ long-term HSCs in aged mice with enhanced quiescence and self-renewal capacity. VarID2 reveals noise dynamics invisible to conventional single-cell transcriptome analysis.}, language = {en} } @article{KayvanpourWisdomLackneretal.2022, author = {Kayvanpour, Elham and Wisdom, Michael and Lackner, Maximilian K. and Sedaghat-Hamedani, Farbod and Boeckel, Jes-Niels and M{\"u}ller, Marion and Eghbalian, Rose and Dudek, Jan and Doroudgar, Shirin and Maack, Christoph and Frey, Norbert and Meder, Benjamin}, title = {VARS2 depletion leads to activation of the integrated stress response and disruptions in mitochondrial fatty acid oxidation}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {13}, issn = {1422-0067}, doi = {10.3390/ijms23137327}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284590}, year = {2022}, abstract = {Mutations in mitochondrial aminoacyl-tRNA synthetases (mtARSs) have been reported in patients with mitochondriopathies: most commonly encephalopathy, but also cardiomyopathy. Through a GWAS, we showed possible associations between mitochondrial valyl-tRNA synthetase (VARS2) dysregulations and non-ischemic cardiomyopathy. We aimed to investigate the possible consequences of VARS2 depletion in zebrafish and cultured HEK293A cells. Transient VARS2 loss-of-function was induced in zebrafish embryos using Morpholinos. The enzymatic activity of VARS2 was measured in VARS2-depleted cells via northern blot. Heterozygous VARS2 knockout was established in HEK293A cells using CRISPR/Cas9 technology. BN-PAGE and SDS-PAGE were used to investigate electron transport chain (ETC) complexes, and the oxygen consumption rate and extracellular acidification rate were measured using a Seahorse XFe96 Analyzer. The activation of the integrated stress response (ISR) and possible disruptions in mitochondrial fatty acid oxidation (FAO) were explored using RT-qPCR and western blot. Zebrafish embryos with transient VARS2 loss-of-function showed features of heart failure as well as indications of CNS and skeletal muscle involvements. The enzymatic activity of VARS2 was significantly reduced in VARS2-depleted cells. Heterozygous VARS2-knockout cells showed a rearrangement of ETC complexes in favor of complexes III\(_2\), III\(_2\) + IV, and supercomplexes without significant respiratory chain deficiencies. These cells also showed the enhanced activation of the ISR, as indicated by increased eIF-2α phosphorylation and a significant increase in the transcript levels of ATF4, ATF5, and DDIT3 (CHOP), as well as disruptions in FAO. The activation of the ISR and disruptions in mitochondrial FAO may underlie the adaptive changes in VARS2-depleted cells.}, language = {en} } @article{GuggenbergerTorreLudwigetal.2022, author = {Guggenberger, Konstanze Viktoria and Torre, Giulia Dalla and Ludwig, Ute and Vogel, Patrick and Weng, Andreas Max and Vogt, Marius Lothar and Fr{\"o}hlich, Matthias and Schmalzing, Marc and Raithel, Esther and Forman, Christoph and Urbach, Horst and Meckel, Stephan and Bley, Thorsten Alexander}, title = {Vasa vasorum of proximal cerebral arteries after dural crossing - potential imaging confounder in diagnosing intracranial vasculitis in elderly subjects on black-blood MRI}, series = {European Radiology}, volume = {32}, journal = {European Radiology}, number = {2}, issn = {1432-1084}, doi = {10.1007/s00330-021-08181-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266524}, pages = {1276-1284}, year = {2022}, abstract = {Objectives Vessel wall enhancement (VWE) may be commonly seen on MRI images of asymptomatic subjects. This study aimed to characterize the VWE of the proximal internal carotid (ICA) and vertebral arteries (VA) in a non-vasculitic elderly patient cohort. Methods Cranial MRI scans at 3 Tesla were performed in 43 patients (aged ≥ 50 years) with known malignancy for exclusion of cerebral metastases. For vessel wall imaging (VWI), a high-resolution compressed-sensing black-blood 3D T1-weighted fast (turbo) spin echo sequence (T1 CS-SPACE prototype) was applied post gadolinium with an isotropic resolution of 0.55 mm. Bilateral proximal intradural ICA and VA segments were evaluated for presence, morphology, and longitudinal extension of VWE. Results Concentric VWE of the proximal intradural ICA was found in 13 (30\%) patients, and of the proximal intradural VA in 39 (91\%) patients. Mean longitudinal extension of VWE after dural entry was 13 mm in the VA and 2 mm in the ICA. In 14 of 39 patients (36\%) with proximal intradural VWE, morphology of VWE was suggestive of the mere presence of vasa vasorum. In 25 patients (64 \%), morphology indicated atherosclerotic lesions in addition to vasa vasorum. Conclusions Vasa vasorum may account for concentric VWE within the proximal 2 mm of the ICA and 13 mm of the VA after dural entry in elderly subjects. Concentric VWE in these locations should not be confused with large artery vasculitis. Distal to these segments, VWE may be more likely related to pathologic conditions such as vasculitis.}, language = {en} } @article{BuschHoffjanBergmannetal.2016, author = {Busch, Albert and Hoffjan, Sabine and Bergmann, Frauke and Hartung, Birgit and Jung, Helena and Hanel, Daniela and Tzschach, Andeas and Kadar, Janos and von Kodolitsch, Yskert and Germer, Christoph-Thomas and Trobisch, Heiner and Strasser, Erwin and Wildenauer, Ren{\´e}}, title = {Vascular type Ehlers-Danlos syndrome is associated with platelet dysfunction and low vitamin D serum concentration}, series = {Orphanet Journal of Rare Diseases}, volume = {11}, journal = {Orphanet Journal of Rare Diseases}, number = {111}, doi = {10.1186/s13023-016-0491-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147757}, year = {2016}, abstract = {Background The vascular type represents a very rare, yet the clinically most fatal entity of Ehlers-Danlos syndrome (EDS). Patients are often admitted due to arterial bleedings and the friable tissue and the altered coagulation contribute to the challenge in treatment strategies. Until now there is little information about clotting characteristics that might influence hemostasis decisively and eventually worsen emergency situations. Results 22 vascular type EDS patients were studied for hemoglobin, platelet volume and count, Quick and activated partial thromboplastin time, fibrinogen, factor XIII, von Willebrand disease, vitamin D and platelet aggregation by modern standard laboratory methods. Results show a high prevalence of over 50 \% for platelet aggregation disorders in vascular type EDS patients, especially for collagen and epinephrine induced tests, whereas the plasmatic cascade did not show any alterations. Additionally, more than half of the tested subjects showed low vitamin D serum levels, which might additionally affect vascular wall integrity. Conclusion The presented data underline the importance of detailed laboratory screening methods in vascular type EDS patients in order to allow for targeted application of platelet-interacting substances that might be of decisive benefit in the emergency setting.}, language = {en} } @article{MatlachFreibergGadeholtetal.2013, author = {Matlach, Juliane and Freiberg, Florentina J. and Gadeholt, Ottar and G{\"o}bel, Winfried}, title = {Vasculitis-like hemorrhagic retinal angiopathy in Wegener's granulomatosis}, series = {BMC Research Notes}, volume = {6}, journal = {BMC Research Notes}, number = {364}, doi = {10.1186/1756-0500-6-364}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128744}, year = {2013}, abstract = {Background: Granulomatosis with polyangiitis, also known as Wegener's granulomatosis, is a chronic systemic inflammatory disease that can also involve the eyes. We report a case of massive retinal and preretinal hemorrhages with perivascular changes as the initial signs in granulomatosis with polyangiitis (Wegener's granulomatosis). Case presentation: A 39-year-old Caucasian male presented with blurred vision in his right eye, myalgia and arthralgia, recurrent nose bleeds and anosmia. Fundus image of his right eye showed massive retinal hemorrhages and vasculitis-like angiopathy, although no fluorescein extravasation was present in fluorescein angiography. Laboratory investigations revealed an inflammation with increased C-reactive protein, elevated erythrocyte sedimentation rate and neutrophil count. Tests for antineutrophil cytoplasmic antibodies (ANCA) were positive for c-ANCA (cytoplasmatic ANCA) and PR3-ANCA (proteinase 3-ANCA). Renal biopsy demonstrated a focal segmental necrotizing glomerulonephritis. Granulomatosis with polyangiitis (Wegener's granulomatosis) was diagnosed and a combined systemic therapy of cyclophosphamide and corticosteroids was initiated. During 3 months of follow-up, complete resorption of retinal hemorrhages was seen and general complaints as well as visual acuity improved during therapy. Conclusion: Vasculitis-like retinal changes can occur in Wegener's granulomatosis. Despite massive retinal and preretinal hemorrhages that cause visual impairment, immunosuppressive therapy can improve ocular symptoms.}, language = {en} } @article{HaarmannVollmuthKollikowskietal.2023, author = {Haarmann, Axel and Vollmuth, Christoph and Kollikowski, Alexander M. and Heuschmann, Peter U. and Pham, Mirko and Stoll, Guido and Neugebauer, Hermann and Schuhmann, Michael K.}, title = {Vasoactive soluble endoglin: a novel biomarker indicative of reperfusion after cerebral large-vessel occlusion}, series = {Cells}, volume = {12}, journal = {Cells}, number = {2}, issn = {2073-4409}, doi = {10.3390/cells12020288}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304995}, year = {2023}, abstract = {Now that mechanical thrombectomy has substantially improved outcomes after large-vessel occlusion stroke in up to every second patient, futile reperfusion wherein successful recanalization is not followed by a favorable outcome is moving into focus. Unfortunately, blood-based biomarkers, which identify critical stages of hemodynamically compromised yet reperfused tissue, are lacking. We recently reported that hypoxia induces the expression of endoglin, a TGF-β co-receptor, in human brain endothelium in vitro. Subsequent reoxygenation resulted in shedding. Our cell model suggests that soluble endoglin compromises the brain endothelial barrier function. To evaluate soluble endoglin as a potential biomarker of reperfusion (-injury) we analyzed its concentration in 148 blood samples of patients with acute stroke due to large-vessel occlusion. In line with our in vitro data, systemic soluble endoglin concentrations were significantly higher in patients with successful recanalization, whereas hypoxia alone did not induce local endoglin shedding, as analyzed by intra-arterial samples from hypoxic vasculature. In patients with reperfusion, higher concentrations of soluble endoglin additionally indicated larger infarct volumes at admission. In summary, we give translational evidence that the sequence of hypoxia and subsequent reoxygenation triggers the release of vasoactive soluble endoglin in large-vessel occlusion stroke and can serve as a biomarker for severe ischemia with ensuing recanalization/reperfusion.}, language = {en} } @article{PlakhutinZhidomirovArbuznikov1992, author = {Plakhutin, B. N. and Zhidomirov, G. M. and Arbuznikov, Alexei V.}, title = {Vector coupling coefficients for calculations of transition-metal atoms and ions by the SCF coupling operator method}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30702}, year = {1992}, abstract = {No abstract available}, language = {en} }