TY  - JOUR
A1  - Manchia, Mirko
A1  - Adli, Mazda
A1  - Akula, Nirmala
A1  - Arda, Raffaella
A1  - Aubry, Jean-Michel
A1  - Backlund, Lena
A1  - Banzato, Claudio E. M.
A1  - Baune, Bernhard T.
A1  - Bellivier, Frank
A1  - Bengesser, Susanne
A1  - Biernacka, Joanna M.
A1  - Brichant-Petitjean, Clara
A1  - Bui, Elise
A1  - Calkin, Cynthia V.
A1  - Cheng, Andrew Tai Ann
A1  - Chillotti, Caterina
A1  - Cichon, Sven
A1  - Clark, Scott
A1  - Czerski, Piotr M.
A1  - Dantas, Clarissa
A1  - Del Zompo, Maria
A1  - DePaulo, J. Raymond
A1  - Detera-Wadleigh, Sevilla D.
A1  - Etain, Bruno
A1  - Falkai, Peter
A1  - Frisén, Louise
A1  - Frye, Mark A.
A1  - Fullerton, Jan
A1  - Gard, Sébastien
A1  - Garnham, Julie
A1  - Goes, Fernando S.
A1  - Grof, Paul
A1  - Gruber, Oliver
A1  - Hashimoto, Ryota
A1  - Hauser, Joanna
A1  - Heilbronner, Urs
A1  - Hoban, Rebecca
A1  - Hou, Liping
A1  - Jamain, Stéphane
A1  - Kahn, Jean-Pierre
A1  - Kassem, Layla
A1  - Kato, Tadafumi
A1  - Kelsoe, John R.
A1  - Kittel-Schneider, Sarah
A1  - Kliwicki, Sebastian
A1  - Kuo, Po-Hsiu
A1  - Kusumi, Ichiro
A1  - Laje, Gonzalo
A1  - Lavebratt, Catharina
A1  - Leboyer, Marion
A1  - Leckband, Susan G.
A1  - López Jaramillo, Carlos A.
A1  - Maj, Mario
A1  - Malafosse, Alain
A1  - Martinsson, Lina
A1  - Masui, Takuya
A1  - Mitchell, Philip B.
A1  - Mondimore, Frank
A1  - Monteleone, Palmiero
A1  - Nallet, Audrey
A1  - Neuner, Maria
A1  - Novák, Tomás
A1  - O'Donovan, Claire
A1  - Ösby, Urban
A1  - Ozaki, Norio
A1  - Perlis, Roy H.
A1  - Pfennig, Andrea
A1  - Potash, James B.
A1  - Reich-Erkelenz, Daniela
A1  - Reif, Andreas
A1  - Reininghaus, Eva
A1  - Richardson, Sara
A1  - Rouleau, Guy A.
A1  - Rybakowski, Janusz K.
A1  - Schalling, Martin
A1  - Schofield, Peter R.
A1  - Schubert, Oliver K.
A1  - Schweizer, Barbara
A1  - Seemüller, Florian
A1  - Grigoroiu-Serbanescu, Maria
A1  - Severino, Giovanni
A1  - Seymour, Lisa R.
A1  - Slaney, Claire
A1  - Smoller, Jordan W.
A1  - Squassina, Alessio
A1  - Stamm, Thomas
A1  - Steele, Jo
A1  - Stopkova, Pavla
A1  - Tighe, Sarah K.
A1  - Tortorella, Alfonso
A1  - Turecki, Gustavo
A1  - Wray, Naomi R.
A1  - Wright, Adam
A1  - Zandi, Peter P.
A1  - Zilles, David
A1  - Bauer, Michael
A1  - Rietschel, Marcella
A1  - McMahon, Francis J.
A1  - Schulze, Thomas G.
A1  - Alda, Martin
T1  - Assessment of Response to Lithium Maintenance Treatment in Bipolar Disorder: A Consortium on Lithium Genetics (ConLiGen) Report
JF  - PLoS ONE
N2  - Objective: The assessment of response to lithium maintenance treatment in bipolar disorder (BD) is complicated by variable length of treatment, unpredictable clinical course, and often inconsistent compliance. Prospective and retrospective methods of assessment of lithium response have been proposed in the literature. In this study we report the key phenotypic measures of the "Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder" scale currently used in the Consortium on Lithium Genetics (ConLiGen) study. 
Materials and Methods: Twenty-nine ConLiGen sites took part in a two-stage case-vignette rating procedure to examine inter-rater agreement [Kappa (\(\kappa\))] and reliability [intra-class correlation coefficient (ICC)] of lithium response. Annotated first-round vignettes and rating guidelines were circulated to expert research clinicians for training purposes between the two stages. Further, we analyzed the distributional properties of the treatment response scores available for 1,308 patients using mixture modeling. 
Results: Substantial and moderate agreement was shown across sites in the first and second sets of vignettes (\(\kappa\) = 0.66 and \(\kappa\) = 0.54, respectively), without significant improvement from training. However, definition of response using the A score as a quantitative trait and selecting cases with B criteria of 4 or less showed an improvement between the two stages (\(ICC_1 = 0.71\) and \(ICC_2 = 0.75\), respectively). Mixture modeling of score distribution indicated three subpopulations (full responders, partial responders, non responders). 
Conclusions: We identified two definitions of lithium response, one dichotomous and the other continuous, with moderate to substantial inter-rater agreement and reliability. Accurate phenotypic measurement of lithium response is crucial for the ongoing ConLiGen pharmacogenomic study.
KW  - age
KW  - observer agreement
KW  - prophylactic lithium
KW  - mapping susceptibility genes
KW  - mood disorders
KW  - onset
KW  - association
KW  - reliability
KW  - morality
KW  - illness
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130938
VL  - 8
IS  - 6
ER  - 
TY  - JOUR
A1  - Reiter, Theresa
A1  - Gensler, Daniel
A1  - Ritter, Oliver
A1  - Weiss, Ingo
A1  - Geistert, Wolfgang
A1  - Kaufmann, Ralf
A1  - Hoffmeister, Sabine
A1  - Friedrich, Michael T.
A1  - Wintzheimer, Stefan
A1  - Düring, Markus
A1  - Nordbeck, Peter
A1  - Jakob, Peter M.
A1  - Ladd, Mark E.
A1  - Quick, Harald H.
A1  - Bauer, Wolfgang R.
T1  - Direct cooling of the catheter tip increases safety for CMR-guided electrophysiological procedures
JF  - Journal of Cardiovascular Magnetic Resonance
N2  - Background: One of the safety concerns when performing electrophysiological (EP) procedures under magnetic resonance (MR) guidance is the risk of passive tissue heating due to the EP catheter being exposed to the radiofrequency (RF) field of the RF transmitting body coil. Ablation procedures that use catheters with irrigated tips are well established therapeutic options for the treatment of cardiac arrhythmias and when used in a modified mode might offer an additional system for suppressing passive catheter heating. 
Methods: A two-step approach was chosen. Firstly, tests on passive catheter heating were performed in a 1.5 T Avanto system (Siemens Healthcare Sector, Erlangen, Germany) using a ASTM Phantom in order to determine a possible maximum temperature rise. Secondly, a phantom was designed for simulation of the interface between blood and the vascular wall. The MR-RF induced temperature rise was simulated by catheter tip heating via a standard ablation generator. Power levels from 1 to 6 W were selected. Ablation duration was 120 s with no tip irrigation during the first 60 s and irrigation at rates from 2 ml/min to 35 ml/min for the remaining 60 s (Biotronik Qiona Pump, Berlin, Germany). The temperature was measured with fluoroscopic sensors (Luxtron, Santa Barbara, CA, USA) at a distance of 0 mm, 2 mm, 4 mm, and 6 mm from the catheter tip. Results: A maximum temperature rise of 22.4 degrees C at the catheter tip was documented in the MR scanner. This temperature rise is equivalent to the heating effect of an ablator's power output of 6 W at a contact force of the weight of 90 g (0.883 N). The catheter tip irrigation was able to limit the temperature rise to less than 2 degrees C for the majority of examined power levels, and for all examined power levels the residual temperature rise was less than 8 degrees C. 
Conclusion: Up to a maximum of 22.4 degrees C, the temperature rise at the tissue surface can be entirely suppressed by using the catheter's own irrigation system. The irrigated tip system can be used to increase MR safety of EP catheters by suppressing the effects of unwanted passive catheter heating due to RF exposure from the MR scanner.
KW  - EP Procedures
KW  - radiofrequency ablation
KW  - contact force
KW  - lesion size
KW  - MRI
KW  - temperature
KW  - tissue
KW  - wires
KW  - model
KW  - ablation
KW  - safety
KW  - catheter tip
KW  - MR guidance
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134927
VL  - 14
IS  - 12
ER  - 
TY  - JOUR
A1  - Nordbeck, Peter
A1  - Bönhof, Leoni
A1  - Hiller, Karl-Heinz
A1  - Voll, Sabine
A1  - Arias-Loza, Paula
A1  - Seidlmaier, Lea
A1  - Williams, Tatjana
A1  - Ye, Yu-Xiang
A1  - Gensler, Daniel
A1  - Pelzer, Theo
A1  - Ertl, Georg
A1  - Jakob, Peter M.
A1  - Bauer, Wolfgang R.
A1  - Ritter, Oliver
T1  - Impact of Thoracic Surgery on Cardiac Morphology and Function in Small Animal Models of Heart Disease: A Cardiac MRI Study in Rats
JF  - PLoS ONE
N2  - Background
Surgical procedures in small animal models of heart disease might evoke alterations in cardiac morphology and function. The aim of this study was to reveal and quantify such potential artificial early or long term effects in vivo, which might account for a significant bias in basic cardiovascular research, and, therefore, could potentially question the meaning of respective studies.

Methods
Female Wistar rats (n = 6 per group) were matched for weight and assorted for sham left coronary artery ligation or control. Cardiac morphology and function was then investigated in vivo by cine magnetic resonance imaging at 7 Tesla 1 and 8 weeks after the surgical procedure. The time course of metabolic and inflammatory blood parameters was determined in addition.

Results
Compared to healthy controls, rats after sham surgery showed a lower body weight both 1 week (267.5±10.6 vs. 317.0±11.3 g, n<0.05) and 8 weeks (317.0±21.1 vs. 358.7±22.4 g, n<0.05) after the intervention. Left and right ventricular morphology and function were not different in absolute measures in both groups 1 week after surgery. However, there was a confined difference in several cardiac parameters normalized to the body weight (bw), such as myocardial mass (2.19±0.30/0.83±0.13 vs. 1.85±0.22/0.70±0.07 mg left/right per g bw, p<0.05), or enddiastolic ventricular volume (1.31±0.36/1.21±0.31 vs. 1.14±0.20/1.07±0.17 µl left/right per g bw, p<0.05). Vice versa, after 8 weeks, cardiac masses, volumes, and output showed a trend for lower values in sham operated rats compared to controls in absolute measures (782.2±57.2/260.2±33.2 vs. 805.9±84.8/310.4±48.5 mg, p<0.05 for left/right ventricular mass), but not normalized to body weight. Matching these findings, blood testing revealed only minor inflammatory but prolonged metabolic changes after surgery not related to cardiac disease.

Conclusion
Cardio-thoracic surgical procedures in experimental myocardial infarction cause distinct alterations upon the global integrity of the organism, which in the long term also induce circumscribed repercussions on cardiac morphology and function. This impact has to be considered when analyzing data from respective animal studies and transferring these findings to conditions in patients.
KW  - heart rate
KW  - body weight
KW  - surgical and invasive medical procedures
KW  - magnetic resonance imaging
KW  - blood
KW  - vascular surgery
KW  - myocardial infarction
KW  - cardiac ventricles
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130064
VL  - 8
IS  - 8
ER  - 
TY  - JOUR
A1  - Gotschy, Alexander
A1  - Bauer, Wolfgang R.
A1  - Winter, Patrick
A1  - Nordbeck, Peter
A1  - Rommel, Eberhard
A1  - Jakob, Peter M.
A1  - Herold, Volker
T1  - Local versus global aortic pulse wave velocity in early atherosclerosis: An animal study in ApoE\(^{-/-}\) mice using ultrahigh field MRI
JF  - PLoS ONE
N2  - Increased aortic stiffness is known to be associated with atherosclerosis and has a predictive value for cardiovascular events. This study aims to investigate the local distribution of early arterial stiffening due to initial atherosclerotic lesions. Therefore, global and local pulse wave velocity (PWV) were measured in ApoE\(^{-/-}\) and wild type (WT) mice using ultrahigh field MRI. For quantification of global aortic stiffness, a new multi-point transit-time (TT) method was implemented and validated to determine the global PWV in the murine aorta. Local aortic stiffness was measured by assessing the local PWV in the upper abdominal aorta, using the flow/area (QA) method. Significant differences between age matched ApoE\(^{-/-}\) and WT mice were determined for global and local PWV measurements (global PWV: ApoE\(^{-/-}\): 2.7 ±0.2m/s vs WT: 2.1±0.2m/s, P<0.03; local PWV: ApoE\(^{-/-}\): 2.9±0.2m/s vs WT: 2.2±0.2m/s, P<0.03). Within the WT mouse group, the global PWV correlated well with the local PWV in the upper abdominal aorta (R\(^2\) = 0.75, P<0.01), implying a widely uniform arterial elasticity.
In ApoE\(^{-/-}\) animals, however, no significant correlation between individual local and global PWV was present (R\(^2\) = 0.07, P = 0.53), implying a heterogeneous distribution of vascular stiffening in early atherosclerosis. The assessment of global PWV using the new multi-point TT measurement technique was validated against a pressure wire measurement in a vessel
phantom and showed excellent agreement. The experimental results demonstrate that vascular stiffening caused by early atherosclerosis is unequally distributed over the length of large vessels. This finding implies that assessing heterogeneity of arterial stiffness by multiple local measurements of PWV might be more sensitive than global PWV to identify early atherosclerotic lesions.
KW  - MRI
KW  - Atherosclerosis
KW  - Aorta
KW  - Stiffness
KW  - Measurement
KW  - Time measurement
KW  - Magnetic resonance imaging
KW  - Mouse models
KW  - Systole
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171824
VL  - 12
IS  - 2
ER  - 
TY  - JOUR
A1  - Reiter, Theresa
A1  - Ritter, Oliver
A1  - Prince, Martin R.
A1  - Nordbeck, Peter
A1  - Wanner, Christoph
A1  - Nagel, Eike
A1  - Bauer, Wolfgang R.
T1  - Minimizing Risk of Nephrogenic systemic fibrosis in Cardiovascular Magnetic Resonance
N2  - Nephrogenic Systemic Fibrosis is a rare condition appearing only in patients with severe renal impairment or failure and presents with dermal lesions and involvement of internal organs. Although many cases are mild, an estimated 5 % have a progressive debilitating course. To date, there is no known effective treatment thus stressing the necessity of ample prevention measures. An association with the use of Gadolinium based contrast agents (GBCA) makes Nephrogenic Systemic Fibrosis a potential side effect of contrast enhanced magnetic resonance imaging and offers the opportunity for prevention by limiting use of gadolinium based contrast agents in renal failure patients. In itself toxic, Gadolinium is embedded into chelates that allow its safe use as a contrast agent. One NSF theory is that Gadolinium chelates distribute into the extracellular fluid compartment and set Gadolinium ions free, depending on multiple factors among which the duration of chelates exposure is directly related to the renal function. Major medical societies both in Europe and in North America have developed guidelines for the usage of GBCA. Since the establishment of these guidelines and the increased general awareness of this condition, the occurrence of NSF has been nearly eliminated. Giving an overview over the current knowledge of NSF pathobiochemistry, pathogenesis and treatment options this review focuses on the guidelines of the European Medicines Agency, the European Society of Urogenital Radiology, the FDA and the American College of Radiology from 2008 up to 2011 and the transfer of this knowledge into every day practice.
KW  - CMR
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75068
ER  - 
TY  - JOUR
A1  - Parczyk, Marco
A1  - Herold, Volker
A1  - Klug, Gert
A1  - Bauer, Wolfgang R.
A1  - Rommel, Eberhard
A1  - Jakob, Peter M.
T1  - Regional in vivo transit time measurements of aortic pulse wave velocity in mice with high-field CMR at 17.6 Tesla
N2  - Background: Transgenic mouse models are increasingly used to study the pathophysiology of human cardiovascular diseases. The aortic pulse wave velocity (PWV) is an indirect measure for vascular stiffness and a marker for cardiovascular risk. Results: This study presents a cardiovascular magnetic resonance (CMR) transit time (TT) method that allows the determination of the PWV in the descending murine aorta by analyzing blood flow waveforms. Systolic flow pulses were recorded with a temporal resolution of 1 ms applying phase velocity encoding. In a first step, the CMR method was validated by pressure waveform measurements on a pulsatile elastic vessel phantom. In a second step, the CMR method was applied to measure PWVs in a group of five eight-month-old apolipoprotein E deficient (ApoE(-/-)) mice and an age matched group of four C57Bl/6J mice. The ApoE(-/-) group had a higher mean PWV (PWV = 3.0 ± 0.6 m/s) than the C57Bl/6J group (PWV = 2.4 ± 0.4 m/s). The difference was statistically significant (p = 0.014). Conclusions: The findings of this study demonstrate that high field CMR is applicable to non-invasively determine and distinguish PWVs in the arterial system of healthy and diseased groups of mice.
KW  - Medizin
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68219
ER  - 
TY  - JOUR
A1  - Reiter, Theresa
A1  - Ritter, Oliver
A1  - Nordbeck, Peter
A1  - Beer, Meinrad
A1  - Bauer, Wolfgang Rudolf
T1  - MRI-guided ablation of wide complex tachycardia in a univentricular heart
JF  - World Journal of Cardiology
N2  - Magnetic resonance imaging can be used for preprocedural assessment of complex anatomy for radiofrequency (RF) ablations, e.g., in a univentricular heart. This case report features the treatment of a young patient with a functionally univentricular heart who suffered from persistent sudden onset tachycardia with wide complexes that required RF ablation as treatment.
KW  - magnetic resonsance imaging
KW  - ablation
KW  - Fontan’s Operation
KW  - ventricular tachycardia
KW  - univentricular heart
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123165
VL  - 4
IS  - 8
ER  - 
TY  - JOUR
A1  - Nordbeck, Peter
A1  - Beer, Meinrad
A1  - Köstler, Herbert
A1  - Ladd, Mark E.
A1  - Quick, Harald H.
A1  - Bauer, Wolfgang R.
A1  - Ritter, Oliver
T1  - Cardiac catheter ablation under real-time magnetic resonance guidance
JF  - European Heart Journal
N2  - One of the main shortcomings of interventional electrophysiology (EP) is its inability to generate sufficient soft tissue contrast for intra-procedural visualization of the myocardium and the surrounding tissue, using conventional imaging techniques. Interventional cardiovascular magnetic resonance imaging (MRI) aims at bringing about significant improvements to the complex and decisive EP interventions far beyond the capabilities of currently available supportive imaging techniques used to surmount the drawbacks of fluoroscopy, as MRI not only allows of precise three-dimensional exposure of the cardiovascular morphology, but also proves to be a promising technique exclusively suitable for direct visualization of arrhythmogenic substrate and therapeutic effects. The major challenge posed by clinical …
KW  - magnetic resonance
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125638
VL  - 33
IS  - 15
ER  - 
TY  - JOUR
A1  - Blömer, Nadja
A1  - Pachel, Christina
A1  - Hofmann, Urlich
A1  - Nordbeck, Peter
A1  - Bauer, Wolfgang
A1  - Mathes, Denise
A1  - Frey, Anna
A1  - Bayer, Barbara
A1  - Vogel, Benjamin
A1  - Ertl, Georg
T1  - 5-Lipoxygenase facilitates healing after myocardial infarction
JF  - Basic Research in Cardiology
N2  - Early healing after myocardial infarction (MI) is characterized by a strong inflammatory reaction. Most leukotrienes are pro-inflammatory and are therefore potential mediators of healing and remodeling after myocardial ischemia. The enzyme 5-lipoxygenase (5-LOX) has a key role in the transformation of arachidonic acid in leukotrienes. Thus, we tested the effect of 5-LOX on healing after MI. After chronic coronary artery ligation, early mortality was significantly increased in 5-LOX\(^{−/−}\) when compared to matching wildtype (WT) mice due to left ventricular rupture. This effect could be reproduced in mice treated with the 5-LOX inhibitor Zileuton. A perfusion mismatch due to the vasoactive potential of leukotrienes is not responsible for left ventricular rupture since local blood flow assessed by magnetic resonance perfusion measurements was not different. However, after MI, there was an accentuation of the inflammatory reaction with an increase of pro-inflammatory macrophages. Yet, mortality was not changed in chimeric mice (WT vs. 5-LOX\(^{−/−}\) bone marrow in 5-LOX\(^{−/−}\) animals), indicating that an altered function of 5-LOX\(^{−/−}\) inflammatory cells is not responsible for the phenotype. Collagen production and accumulation of fibroblasts were significantly reduced in 5-LOX\(^{−/−}\) mice in vivo after MI. This might be due to an impaired migration of 5-LOX\(^{−/−}\) fibroblasts, as shown in vitro to serum. In conclusion, a lack or inhibition of 5-LOX increases mortality after MI because of healing defects. This is not mediated by a change in local blood flow, but through an altered inflammation and/or fibroblast function.
KW  - lipoxygenase
KW  - myocardial infarction
KW  - extracellular matrix remodeling
KW  - inflammation
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132602
VL  - 108
IS  - 4
ER  - 
TY  - JOUR
A1  - Grabenhenrich, Linus B.
A1  - Reich, Andreas
A1  - Fischer, Felix
A1  - Zepp, Fred
A1  - Forster, Johannes
A1  - Schuster, Antje
A1  - Bauer, Carl-Peter
A1  - Bergmann, Renate L.
A1  - Bergmann, Karl E.
A1  - Wahn, Ulrich
A1  - Keil, Thomas
A1  - Lau, Susanne
T1  - The Novel 10-Item Asthma Prediction Tool: External Validation in the German MAS Birth Cohort
JF  - PLOS ONE
N2  - Background: A novel non-invasive asthma prediction tool from the Leicester Cohort, UK, forecasts asthma at age 8 years based on 10 predictors assessed in early childhood, including current respiratory symptoms, eczema, and parental history of asthma. 
Objective: We aimed to externally validate the proposed asthma prediction method in a German birth cohort. 
Methods: The MAS-90 study (Multicentre Allergy Study) recorded details on allergic diseases prospectively in about yearly follow-up assessments up to age 20 years in a cohort of 1,314 children born 1990. We replicated the scoring method from the Leicester cohort and assessed prediction, performance and discrimination. The primary outcome was defined as the combination of parent-reported wheeze and asthma drugs (both in last 12 months) at age 8. Sensitivity analyses assessed model performance for outcomes related to asthma up to age 20 years. Results: For 140 children parents reported current wheeze or cough at age 3 years. Score distribution and frequencies of later asthma resembled the Leicester cohort: 9% vs. 16% (MAS-90 vs. Leicester) of children at low risk at 3 years had asthma at 8 years, at medium risk 45% vs. 48%. Performance of the asthma prediction tool in the MAS-90 cohort was similar (Brier score 0.22 vs. 0.23) and discrimination slightly better than in the original cohort (area under the curve, AUC 0.83 vs. 0.78). Prediction and discrimination were robust against changes of inclusion criteria, scoring and outcome definitions. The secondary outcome 'physicians' diagnosed asthma at 20 years' showed the highest discrimination (AUC 0.89). 
Conclusion: The novel asthma prediction tool from the Leicester cohort, UK, performed well in another population, a German birth cohort, supporting its use and further development as a simple aid to predict asthma risk in clinical settings.
KW  - disease
KW  - models
KW  - symptoms
KW  - risk
KW  - early-life
KW  - young children
KW  - preschool children
KW  - sample
KW  - wheeze
KW  - age
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114202
SN  - 1932-6203
VL  - 9
IS  - 12
ER  - 
TY  - JOUR
A1  - Mueller, Thomas D.
A1  - Fiebig, Juliane E.
A1  - Weidauer, Stella E.
A1  - Qiu, Li-Yan
A1  - Bauer, Markus
A1  - Schmieder, Peter
A1  - Beerbaum, Monika
A1  - Zhang, Jin-Li
A1  - Oschkinat, Hartmut
A1  - Sebald, Walter
T1  - The Clip-Segment of the von Willebrand Domain 1 of the BMP Modulator Protein Crossveinless 2 Is Preformed
JF  - Molecules
N2  - Bone Morphogenetic Proteins (BMPs) are secreted protein hormones that act as morphogens and exert essential roles during embryonic development of tissues and organs. Signaling by BMPs occurs via hetero-oligomerization of two types of serine/threonine kinase transmembrane receptors. Due to the small number of available receptors for a large number of BMP ligands ligand-receptor promiscuity presents an evident problem requiring additional regulatory mechanisms for ligand-specific signaling. Such additional regulation is achieved through a plethora of extracellular antagonists, among them members of the Chordin superfamily, that modulate BMP signaling activity by binding. The key-element in Chordin-related antagonists for interacting with BMPs is the von Willebrand type C (VWC) module, which is a small domain of about 50 to 60 residues occurring in many different proteins. Although a structure of the VWC domain of the Chordin-member Crossveinless 2 (CV2) bound to BMP-2 has been determined by X-ray crystallography, the molecular mechanism by which the VWC domain binds BMPs has remained unclear. Here we present the NMR structure of the Danio rerio CV2 VWC1 domain in its unbound state showing that the key features for high affinity binding to BMP-2 is a pre-oriented peptide loop.
KW  - bone morphogenetic proteins
KW  - TGF-β superfamily
KW  - BMP antagonist
KW  - protein-protein recognition
KW  - NMR spectroscopy
KW  - von Willebrand type C domain
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-97196
ER  - 
TY  - JOUR
A1  - Winter, Patrick
A1  - Kampf, Thomas
A1  - Helluy, Xavier
A1  - Gutjahr, Fabian T.
A1  - Meyer, Cord B.
A1  - Rommel, Eberhard
A1  - Bauer, Wolfgang R.
A1  - Jakob, Peter M.
A1  - Herold, Volker
T1  - Fast retrospectively triggered local pulse-wave velocity measurements in mice with CMR-microscopy using a radial trajectory
JF  - Journal of Cardiovascular Magnetic Resonance
N2  - Background

The aortic pulse-wave velocity (PWV) is an important indicator of cardiovascular risk. In recent studies MRI methods have been developed to measure this parameter noninvasively in mice. Present techniques require additional hardware for cardiac and respiratory gating. In this work a robust self-gated measurement of the local PWV in mice without the need of triggering probes is proposed.

Methods

The local PWV of 6-months-old wild-type C57BL/6J mice (n=6) was measured in the abdominal aorta with a retrospectively triggered radial Phase Contrast (PC) MR sequence using the flow-area (QA) method. A navigator signal was extracted from the CMR data of highly asymmetric radial projections with short repetition time (TR=3 ms) and post-processed with high-pass and low-pass filters for retrospective cardiac and respiratory gating. The self-gating signal was used for a reconstruction of high-resolution Cine frames of the aortic motion. To assess the local PWV the volume flow Q and the cross-sectional area A of the aorta were determined. The results were compared with the values measured with a triggered Cartesian and an undersampled triggered radial PC-Cine sequence.

Results

In all examined animals a self-gating signal could be extracted and used for retrospective breath-gating and PC-Cine reconstruction. With the non-triggered measurement PWV values of 2.3±0.2 m/s were determined. These values are in agreement with those measured with the triggered Cartesian (2.4±0.2 m/s) and the triggered radial (2.3±0.2 m/s) measurement. Due to the strong robustness of the radial trajectory against undersampling an acceleration of more than two relative to the prospectively triggered Cartesian sampling could be achieved with the retrospective method.

Conclusion

With the radial flow-encoding sequence the extraction of a self-gating signal is feasible. The retrospective method enables a robust and fast measurement of the local PWV without the need of additional trigger hardware.
KW  - pulse-wave velocity
KW  - mouse
KW  - self-gating
KW  - phase-contrast CMR
KW  - non-triggered
KW  - retrospective
KW  - radial
KW  - aorta
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96602
UR  - http://jcmr-online.com/content/15/1/88
ER  - 
TY  - JOUR
A1  - Sepahi, Ilnaz
A1  - Faust, Ulrike
A1  - Sturm, Marc
A1  - Bosse, Kristin
A1  - Kehrer, Martin
A1  - Heinrich, Tilman
A1  - Grundman-Hauser, Kathrin
A1  - Bauer, Peter
A1  - Ossowski, Stephan
A1  - Susak, Hana
A1  - Varon, Raymonda
A1  - Schröck, Evelin
A1  - Niederacher, Dieter
A1  - Auber, Bernd
A1  - Sutter, Christian
A1  - Arnold, Norbert
A1  - Hahnen, Eric
A1  - Dworniczak, Bernd
A1  - Wang-Gorke, Shan
A1  - Gehrig, Andrea
A1  - Weber, Bernhard H. F.
A1  - Engel, Christoph
A1  - Lemke, Johannes R.
A1  - Hartkopf, Andreas
A1  - Huu Phuc, Nguyen
A1  - Riess, Olaf
A1  - Schroeder, Christopher
T1  - Investigating the effects of additional truncating variants in DNA-repair genes on breast cancer risk in BRCA1-positive women
JF  - BMC Cancer
N2  - Background
Inherited pathogenic variants in BRCA1 and BRCA2 are the most common causes of hereditary breast and ovarian cancer (HBOC). The risk of developing breast cancer by age 80 in women carrying a BRCA1 pathogenic variant is 72%. The lifetime risk varies between families and even within affected individuals of the same family. The cause of this variability is largely unknown, but it is hypothesized that additional genetic factors contribute to differences in age at onset (AAO). Here we investigated whether truncating and rare missense variants in genes of different DNA-repair pathways contribute to this phenomenon.

Methods
We used extreme phenotype sampling to recruit 133 BRCA1-positive patients with either early breast cancer onset, below 35 (early AAO cohort) or cancer-free by age 60 (controls). Next Generation Sequencing (NGS) was used to screen for variants in 311 genes involved in different DNA-repair pathways.

Results
Patients with an early AAO (73 women) had developed breast cancer at a median age of 27 years (interquartile range (IQR); 25.00–27.00 years). A total of 3703 variants were detected in all patients and 43 of those (1.2%) were truncating variants. The truncating variants were found in 26 women of the early AAO group (35.6%; 95%-CI 24.7 - 47.7%) compared to 16 women of controls (26.7%; 95%-CI 16.1 to 39.7%). When adjusted for environmental factors and family history, the odds ratio indicated an increased breast cancer risk for those carrying an additional truncating DNA-repair variant to BRCA1 mutation (OR: 3.1; 95%-CI 0.92 to 11.5; p-value = 0.07), although it did not reach the conventionally acceptable significance level of 0.05.

Conclusions
To our knowledge this is the first time that the combined effect of truncating variants in DNA-repair genes on AAO in patients with hereditary breast cancer is investigated. Our results indicate that co-occurring truncating variants might be associated with an earlier onset of breast cancer in BRCA1-positive patients. Larger cohorts are needed to confirm these results.
KW  - breast cancer
KW  - age at onset
KW  - DNA-repair genes
KW  - next-generation-sequencing
KW  - panel sequencing
KW  - extreme phenotypes
KW  - hereditary breast and ovarian cancer
KW  - BRCA1
KW  - DNA-repair
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-237676
VL  - 19
ER  - 
TY  - JOUR
A1  - Winter, Patrick M.
A1  - Andelovic, Kristina
A1  - Kampf, Thomas
A1  - Hansmann, Jan
A1  - Jakob, Peter Michael
A1  - Bauer, Wolfgang Rudolf
A1  - Zernecke, Alma
A1  - Herold, Volker
T1  - Simultaneous measurements of 3D wall shear stress and pulse wave velocity in the murine aortic arch
JF  - Journal of Cardiovascular Magnetic Resonance
N2  - Purpose

Wall shear stress (WSS) and pulse wave velocity (PWV) are important parameters to characterize blood flow in the vessel wall. Their quantification with flow-sensitive phase-contrast (PC) cardiovascular magnetic resonance (CMR), however, is time-consuming. Furthermore, the measurement of WSS requires high spatial resolution, whereas high temporal resolution is necessary for PWV measurements. For these reasons, PWV and WSS are challenging to measure in one CMR session, making it difficult to directly compare these parameters. By using a retrospective approach with a flexible reconstruction framework, we here aimed to simultaneously assess both PWV and WSS in the murine aortic arch from the same 4D flow measurement.

Methods

Flow was measured in the aortic arch of 18-week-old wildtype (n = 5) and ApoE\(^{−/−}\) mice (n = 5) with a self-navigated radial 4D-PC-CMR sequence. Retrospective data analysis was used to reconstruct the same dataset either at low spatial and high temporal resolution (PWV analysis) or high spatial and low temporal resolution (WSS analysis). To assess WSS, the aortic lumen was labeled by semi-automatically segmenting the reconstruction with high spatial resolution. WSS was determined from the spatial velocity gradients at the lumen surface. For calculation of the PWV, segmentation data was interpolated along the temporal dimension. Subsequently, PWV was quantified from the through-plane flow data using the multiple-points transit-time method. Reconstructions with varying frame rates and spatial resolutions were performed to investigate the influence of spatiotemporal resolution on the PWV and WSS quantification.

Results

4D flow measurements were conducted in an acquisition time of only 35 min. Increased peak flow and peak WSS values and lower errors in PWV estimation were observed in the reconstructions with high temporal resolution. Aortic PWV was significantly increased in ApoE\(^{−/−}\) mice compared to the control group (1.7 ± 0.2 versus 2.6 ± 0.2 m/s, p < 0.001). Mean WSS magnitude values averaged over the aortic arch were (1.17 ± 0.07) N/m\(^2\) in wildtype mice and (1.27 ± 0.10) N/m\(^2\) in ApoE\(^{−/−}\) mice.

Conclusion

The post processing algorithm using the flexible reconstruction framework developed in this study permitted quantification of global PWV and 3D-WSS in a single acquisition. The possibility to assess both parameters in only 35 min will markedly improve the analyses and information content of in vivo measurements.
KW  - 4D flow
KW  - pulse wave velocity
KW  - wall shear stress
KW  - radial
KW  - self-navigation
KW  - mouse
KW  - aortic arch
KW  - atherosclerosis
KW  - mice
KW  - flow
KW  - plaque
KW  - CMR
KW  - quantification
KW  - microscopy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259152
VL  - 23
IS  - 1
ER  - 
TY  - JOUR
A1  - Forchert, Leandra
A1  - Potapova, Ekaterina
A1  - Panetta, Valentina
A1  - Dramburg, Stephanie
A1  - Perna, Serena
A1  - Posa, Daniela
A1  - Resch‐Marat, Yvonne
A1  - Lupinek, Christian
A1  - Rohrbach, Alexander
A1  - Grabenhenrich, Linus
A1  - Icke, Katja
A1  - Bauer, Carl‐Peter
A1  - Hoffman, Ute
A1  - Forster, Johannes
A1  - Zepp, Fred
A1  - Schuster, Antje
A1  - Wahn, Ulrich
A1  - Keil, Thomas
A1  - Lau, Susanne
A1  - Vrtala, Susanne
A1  - Valenta, Rudolf
A1  - Matricardi, Paolo Maria
T1  - Der p 23‐specific IgE response throughout childhood and its association with allergic disease: A birth cohort study
JF  - Pediatric Allergy and Immunology
N2  - Background
The Dermatophagoides pteronyssinus molecule Der p 23 is a major allergen whose clinical relevance has been shown in cross‐sectional studies. We longitudinally analysed the trajectory of Der p 23‐specific IgE antibody (sIgE) levels throughout childhood and youth, their early‐life determinants and their clinical relevance for allergic rhinitis and asthma.
Methods
We obtained sera and clinical data of 191 participants of the German Multicentre Allergy Study, a prospective birth cohort. Serum samples from birth to 20 years of age with sIgE reactivity to Der p 23 in a customised semiquantitative microarray were newly analysed with a singleplex quantitative assay. Early mite exposure was assessed by measuring the average content of Der p 1 in house dust at 6 and 18 months.
Results
Der p 23‐sIgE levels were detected at least once in 97/191 participants (51%). Prevalence of Der p 23 sensitisation and mean sIgE levels increased until age 10 years, plateaued until age 13 years and were lowest at age 20 years. Asthma, allergic rhinitis (AR) and atopic dermatitis (AD) were more prevalent in Der p 23‐sensitised children, including those with monomolecular but persistent sensitisation (11/97, 11%). A higher exposure to mites in infancy and occurrence of AD before 5 years of age preceded the onset of Der p 23 sensitisation, which in turn preceded a higher incidence of asthma.
Conclusions
Der p 23 sensitisation peaks in late childhood and then decreases. It is preceded by early mite exposure and AD. Asthma and AR can occur in patients persistently sensitised to Der p 23 as the only mite allergen, suggesting the inclusion of molecular testing of Der p 23‐sIgE for subjects with clinical suspicion of HDM allergy but without sIgE to other major D.pt. allergens.
KW  - asthma
KW  - birth cohort
KW  - childhood
KW  - Der p 23
KW  - house dust mite allergy
KW  - IgE
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-287181
VL  - 33
IS  - 7
ER  - 
TY  - JOUR
A1  - Lüffe, Teresa M.
A1  - D'Orazio, Andrea
A1  - Bauer, Moritz
A1  - Gioga, Zoi
A1  - Schoeffler, Victoria
A1  - Lesch, Klaus-Peter
A1  - Romanos, Marcel
A1  - Drepper, Carsten
A1  - Lillesaar, Christina
T1  - Increased locomotor activity via regulation of GABAergic signalling in foxp2 mutant zebrafish – implications for neurodevelopmental disorders
JF  - Translational Psychiatry
N2  - Recent advances in the genetics of neurodevelopmental disorders (NDDs) have identified the transcription factor FOXP2 as one of numerous risk genes, e.g. in autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD). FOXP2 function is suggested to be involved in GABAergic signalling and numerous studies demonstrate that GABAergic function is altered in NDDs, thus disrupting the excitation/inhibition balance. Interestingly, GABAergic signalling components, including glutamate-decarboxylase 1 (Gad1) and GABA receptors, are putative transcriptional targets of FOXP2. However, the specific role of FOXP2 in the pathomechanism of NDDs remains elusive. Here we test the hypothesis that Foxp2 affects behavioural dimensions via GABAergic signalling using zebrafish as model organism. We demonstrate that foxp2 is expressed by a subset of GABAergic neurons located in brain regions involved in motor functions, including the subpallium, posterior tuberculum, thalamus and medulla oblongata. Using CRISPR/Cas9 gene-editing we generated a novel foxp2 zebrafish loss-of-function mutant that exhibits increased locomotor activity. Further, genetic and/or pharmacological disruption of Gad1 or GABA-A receptors causes increased locomotor activity, resembling the phenotype of foxp2 mutants. Application of muscimol, a GABA-A receptor agonist, rescues the hyperactive phenotype induced by the foxp2 loss-of-function. By reverse translation of the therapeutic effect on hyperactive behaviour exerted by methylphenidate, we note that application of methylphenidate evokes different responses in wildtype compared to foxp2 or gad1b loss-of-function animals. Together, our findings support the hypothesis that foxp2 regulates locomotor activity via GABAergic signalling. This provides one targetable mechanism, which may contribute to behavioural phenotypes commonly observed in NDDs.
KW  - comparative genomics
KW  - molecular neuroscience
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-264713
VL  - 11
ER  - 
TY  - JOUR
A1  - Prantl, Thomas
A1  - Zeck, Timo
A1  - Bauer, Andre
A1  - Ten, Peter
A1  - Prantl, Dominik
A1  - Yahya, Ala Eddine Ben
A1  - Ifflaender, Lukas
A1  - Dmitrienko, Alexandra
A1  - Krupitzer, Christian
A1  - Kounev, Samuel
T1  - A Survey on Secure Group Communication Schemes With Focus on IoT Communication
JF  - IEEE Access
N2  - A key feature for Internet of Things (IoT) is to control what content is available to each user. To handle this access management, encryption schemes can be used. Due to the diverse usage of encryption schemes, there are various realizations of 1-to-1, 1-to-n, and n-to-n schemes in the literature. This multitude of encryption methods with a wide variety of properties presents developers with the challenge of selecting the optimal method for a particular use case, which is further complicated by the fact that there is no overview of existing encryption schemes. To fill this gap, we envision a cryptography encyclopedia providing such an overview of existing encryption schemes. In this survey paper, we take a first step towards such an encyclopedia by creating a sub-encyclopedia for secure group communication (SGC) schemes, which belong to the n-to-n category. We extensively surveyed the state-of-the-art and classified 47 different schemes. More precisely, we provide (i) a comprehensive overview of the relevant security features, (ii) a set of relevant performance metrics, (iii) a classification for secure group communication schemes, and (iv) workflow descriptions of the 47 schemes. Moreover, we perform a detailed performance and security evaluation of the 47 secure group communication schemes. Based on this evaluation, we create a guideline for the selection of secure group communication schemes.
KW  - Internet of Things
KW  - encryption
KW  - secure group communication
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300257
VL  - 10
SP  - 99944
EP  - 99962
ER  - 
TY  - JOUR
A1  - Andelovic, Kristina
A1  - Winter, Patrick
A1  - Kampf, Thomas
A1  - Xu, Anton
A1  - Jakob, Peter Michael
A1  - Herold, Volker
A1  - Bauer, Wolfgang Rudolf
A1  - Zernecke, Alma
T1  - 2D Projection Maps of WSS and OSI Reveal Distinct Spatiotemporal Changes in Hemodynamics in the Murine Aorta during Ageing and Atherosclerosis
JF  - Biomedicines
N2  - Growth, ageing and atherosclerotic plaque development alter the biomechanical forces acting on the vessel wall. However, monitoring the detailed local changes in wall shear stress (WSS) at distinct sites of the murine aortic arch over time has been challenging. Here, we studied the temporal and spatial changes in flow, WSS, oscillatory shear index (OSI) and elastic properties of healthy wildtype (WT, n = 5) and atherosclerotic apolipoprotein E-deficient (Apoe\(^{−/−}\), n = 6) mice during ageing and atherosclerosis using high-resolution 4D flow magnetic resonance imaging (MRI). Spatially resolved 2D projection maps of WSS and OSI of the complete aortic arch were generated, allowing the pixel-wise statistical analysis of inter- and intragroup hemodynamic changes over time and local correlations between WSS, pulse wave velocity (PWV), plaque and vessel wall characteristics. The study revealed converse differences of local hemodynamic profiles in healthy WT and atherosclerotic Apoe\(^{−/−}\) mice, and we identified the circumferential WSS as potential marker of plaque size and composition in advanced atherosclerosis and the radial strain as a potential marker for vascular elasticity. Two-dimensional (2D) projection maps of WSS and OSI, including statistical analysis provide a powerful tool to monitor local aortic hemodynamics during ageing and atherosclerosis. The correlation of spatially resolved hemodynamics and plaque characteristics could significantly improve our understanding of the impact of hemodynamics on atherosclerosis, which may be key to understand plaque progression towards vulnerability.
KW  - atherosclerosis
KW  - mouse
KW  - 4D flow MRI
KW  - aortic arch
KW  - flow dynamics
KW  - WSS
KW  - mapping
KW  - PWV
KW  - plaque characteristics
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-252164
SN  - 2227-9059
VL  - 9
IS  - 12
ER  - 
TY  - JOUR
A1  - Marx, Gernot
A1  - Schindler, Achim W.
A1  - Mosch, Christoph
A1  - Albers, Joerg
A1  - Bauer, Michael
A1  - Gnass, Irmela
A1  - Hobohm, Carsten
A1  - Janssens, Uwe
A1  - Kluge, Stefan
A1  - Kranke, Peter
A1  - Maurer, Tobias
A1  - Merz, Waltraut
A1  - Neugebauer, Edmund
A1  - Quintel, Michael
A1  - Senninger, Norbert
A1  - Trampisch, Hans-Joachim
A1  - Waydhas, Christian
A1  - Wildenauer, Rene
A1  - Zacharowski, Kai
A1  - Eikermann, Michaela
T1  - Intravascular volume therapy in adults guidelines from the association of the scientific medical societies in Germany
JF  - European Journal of Anaesthesiology
N2  - No abstract available.
KW  - Predict fluid responsiveness
KW  - Randomized controlled-trial
KW  - 6-percent hydroxyethyl starch
KW  - Central venous-pressure
KW  - Elective cesarean-section
KW  - Critically-ill patients
KW  - Puls-pressure variation
KW  - Lactated ringers solution
KW  - Hypertonic saline 7.5-percent
KW  - Major abdominal surgery
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-188223
VL  - 33
IS  - 7
ER  - 
TY  - JOUR
A1  - Andelovic, Kristina
A1  - Winter, Patrick
A1  - Jakob, Peter Michael
A1  - Bauer, Wolfgang Rudolf
A1  - Herold, Volker
A1  - Zernecke, Alma
T1  - Evaluation of plaque characteristics and inflammation using magnetic resonance imaging
JF  - Biomedicines
N2  - Atherosclerosis is an inflammatory disease of large and medium-sized arteries, characterized by the growth of atherosclerotic lesions (plaques). These plaques often develop at inner curvatures of arteries, branchpoints, and bifurcations, where the endothelial wall shear stress is low and oscillatory. In conjunction with other processes such as lipid deposition, biomechanical factors lead to local vascular inflammation and plaque growth. There is also evidence that low and oscillatory shear stress contribute to arterial remodeling, entailing a loss in arterial elasticity and, therefore, an increased pulse-wave velocity. Although altered shear stress profiles, elasticity and inflammation are closely intertwined and critical for plaque growth, preclinical and clinical investigations for atherosclerosis mostly focus on the investigation of one of these parameters only due to the experimental limitations. However, cardiovascular magnetic resonance imaging (MRI) has been demonstrated to be a potent tool which can be used to provide insights into a large range of biological parameters in one experimental session. It enables the evaluation of the dynamic process of atherosclerotic lesion formation without the need for harmful radiation. Flow-sensitive MRI provides the assessment of hemodynamic parameters such as wall shear stress and pulse wave velocity which may replace invasive and radiation-based techniques for imaging of the vascular
function and the characterization of early plaque development. In combination with inflammation imaging, the analyses and correlations of these parameters could not only significantly advance basic preclinical investigations of atherosclerotic lesion formation and progression, but also the diagnostic clinical evaluation for early identification of high-risk plaques, which are prone to rupture. In this review, we summarize the key applications of magnetic resonance imaging for the evaluation of plaque characteristics through flow sensitive and morphological measurements. The simultaneous measurements of functional and structural parameters will further preclinical research on atherosclerosis and has the potential to fundamentally improve the detection of inflammation and vulnerable plaques in patients.
KW  - atherosclerosis
KW  - mouse models
KW  - wall shear stress
KW  - pulse wave velocity
KW  - arterial elasticity
KW  - inflammation
KW  - magnetic resonance imaging
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228839
SN  - 2227-9059
VL  - 9
IS  - 2
ER  - 
TY  - JOUR
A1  - Winter, Patrick
A1  - Andelovic, Kristina
A1  - Kampf, Thomas
A1  - Gutjahr, Fabian Tobias
A1  - Heidenreich, Julius
A1  - Zernecke, Alma
A1  - Bauer, Wolfgang Rudolf
A1  - Jakob, Peter Michael
A1  - Herold, Volker
T1  - Fast self-navigated wall shear stress measurements in the murine aortic archusing radial 4D-phase contrast cardiovascular magnetic resonance at 17.6 T
JF  - Journal of Cardiovascular Magnetic Resonance
N2  - Purpose
4D flow cardiovascular magnetic resonance (CMR) and the assessment of wall shear stress (WSS) are non-invasive tools to study cardiovascular risks in vivo. Major limitations of conventional triggered methods are the long measurement times needed for high-resolution data sets and the necessity of stable electrocardiographic (ECG) triggering. In this work an ECG-free retrospectively synchronized method is presented that enables accelerated high-resolution measurements of 4D flow and WSS in the aortic arch of mice.

Methods
4D flow and WSS were measured in the aortic arch of 12-week-old wildtype C57BL/6 J mice (n = 7) with a radial 4D-phase-contrast (PC)-CMR sequence, which was validated in a flow phantom. Cardiac and respiratory motion signals were extracted from the radial CMR signal and were used for the reconstruction of 4D-flow data. Rigid motion correction and a first order B0 correction was used to improve the robustness of magnitude and velocity data.

The aortic lumen was segmented semi-automatically. Temporally averaged and time-resolved WSS and oscillatory shear index (OSI) were calculated from the spatial velocity gradients at the lumen surface at 14 locations along the aortic arch. Reproducibility was tested in 3 animals and the influence of subsampling was investigated.

Results
Volume flow, cross-sectional areas, WSS and the OSI were determined in a measurement time of only 32 min. Longitudinal and circumferential WSS and radial stress were assessed at 14 analysis planes along the aortic arch. The average longitudinal, circumferential and radial stress values were 1.52 ± 0.29 N/m2, 0.28 ± 0.24 N/m2 and − 0.21 ± 0.19 N/m2, respectively. Good reproducibility of WSS values was observed.

Conclusion
This work presents a robust measurement of 4D flow and WSS in mice without the need of ECG trigger signals. The retrospective approach provides fast flow quantification within 35 min and a flexible reconstruction framework.
KW  - 4D flow
KW  - WSS
KW  - OSI
KW  - Self-navigation
KW  - Mouse
KW  - Aortic arch
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201120
VL  - 21
ER  - 
TY  - JOUR
A1  - Herold, Volker
A1  - Herz, Stefan
A1  - Winter, Patrick
A1  - Gutjahr, Fabian Tobias
A1  - Andelovic, Kristina
A1  - Bauer, Wolfgang Rudolf
A1  - Jakob, Peter Michael
T1  - Assessment of local pulse wave velocity distribution in mice using k-t BLAST PC-CMR with semi-automatic area segmentation.
JF  - Journal of Cardiovascular Magnetic Resonance
N2  - Background:
Local aortic pulse wave velocity (PWV) is a measure for vascular stiffness and has a predictive value for cardiovascular events. Ultra high field CMR scanners allow the quantification of local PWV in mice, however these systems are yet unable to monitor the distribution of local elasticities.
Methods:
In the present study we provide a new accelerated method to quantify local aortic PWV in mice with phase-contrast cardiovascular magnetic resonance imaging (PC-CMR) at 17.6 T. Based on a k-t BLAST (Broad-use Linear Acquisition Speed-up Technique) undersampling scheme, total measurement time could be reduced by a factor of 6. The fast data acquisition enables to quantify the local PWV at several locations along the aortic blood vessel based on the evaluation of local temporal changes in blood flow and vessel cross sectional area. To speed up post processing and to eliminate operator bias, we introduce a new semi-automatic segmentation algorithm to quantify cross-sectional areas of the aortic vessel. The new methods were applied in 10 eight-month-old mice (4 C57BL/6J-mice and 6 ApoE\(^{(-/-)}\)-mice) at 12 adjacent locations along the abdominal aorta.
Results:
Accelerated data acquisition and semi-automatic post-processing delivered reliable measures for the local PWV, similiar to those obtained with full data sampling and manual segmentation. No statistically significant differences of the mean values could be detected for the different measurement approaches. Mean PWV values were elevated for the ApoE\(^{(-/-)}\)-group compared to the C57BL/6J-group (3.5 ± 0.7 m/s vs. 2.2 ± 0.4 m/s, p < 0.01). A more heterogeneous PWV-distribution in the ApoE \(^{(-/-)}\)-animals could be observed compared to the C57BL/6J-mice, representing the local character of lesion development in atherosclerosis.
Conclusion:
In the present work, we showed that k-t BLAST PC-MRI enables the measurement of the local PWV distribution in the mouse aorta. The semi-automatic segmentation method based on PC-CMR data allowed rapid determination of local PWV. The findings of this study demonstrate the ability of the proposed methods to non-invasively quantify the spatial variations in local PWV along the aorta of ApoE\(^{(-/-)}\)-mice as a relevant model of atherosclerosis.
KW  - pulse wave velocity
KW  - ApoE\(^{(-/-)}\)
KW  - magnetic resonance imaging
KW  - phase contrast
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-157696
VL  - 19
IS  - 77
ER  - 
TY  - JOUR
A1  - Lawitschka, Anita
A1  - Brunmair, Matthias
A1  - Bauer, Dorothea
A1  - Zubarovskaya, Natalia
A1  - Felder-Puig, Rosemarie
A1  - Strahm, Brigitte
A1  - Bader, Peter
A1  - Strauss, Gabriele
A1  - Albert, Michael
A1  - Luettichau, Irene von
A1  - Greinix, Hildegard
A1  - Wolff, Daniel
A1  - Peters, Christina
T1  - Psychometric properties of the Activities Scale for Kids-performance after allogeneic hematopoietic stem cell transplantation in adolescents and children
BT  - Results of a prospective study on behalf of the German-Austrian-Swiss GVHD Consortium
JF  - Wiener klinische Wochenschrift
N2  - Background
The psychometric properties of an instrument, the Activity Scale for Kids-performance (ASKp), were assessed which was proposed to capture physical functioning after allogeneic hematopoietic stem cell transplantation (HSCT). Additionally, this multicenter observational prospective study investigated the influence of clinical correlates focusing on chronic graft-versus-host disease (cGVHD).

Methods
Patient-reported ASKp, clinician-reported Karnofsky/Lansky status (KPS/PSS), patient characteristics and cGVHD details were assessed of 55 patients with a median age of 12 years at baseline after day +100 post-HSCT and every 3 months during the next 18 months. The psychometric properties were evaluated and ASKp and KPS/PSS status was compared using ANOVAS and multiple regression models.

Results
The German version of the ASKp showed good psychometric properties except for ceiling effects. Discrimination ability of the ASKp was good regarding the need for devices but failed to predict cGVHD patients. Both the ASKp and the KPS/PSS were associated with patients after adoptive cell therapy being in need for devices, suffering from overlap cGVHD and from steroid side effects but not with patients’ age and gender. In contrast to the KPS/PSS the ASKp only showed significant differences after merging moderate and severe cGHVD patients when comparing them to No-cGVHD (F = 4.050; p = 0.049), being outperformed by the KPS/PSS (F = 20.082; p < 0.001).

Conclusion
The ASKp showed no clear advantages compared to KPS/PSS even though economical and patients’ effort was higher. Further application range may be limited through ceiling effects. Both should be taken into consideration. Therefore, the results may not support the usage of ASKp after HSCT and rather suggest KPS/PSS, both patient and clinician reported.
KW  - physical functioning
KW  - cancer patients
KW  - AYAs
KW  - GVHD
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281100
VL  - 133
IS  - 1-2
ER  -