TY  - JOUR
A1  - Mitchell, Jonathan S.
A1  - Li, Ni
A1  - Weinhold, Niels
A1  - Försti, Asta
A1  - Ali, Mina
A1  - van Duin, Mark
A1  - Thorleifsson, Gudmar
A1  - Johnson, David C.
A1  - Chen, Bowang
A1  - Halvarsson, Britt-Marie
A1  - Gudbjartsson, Daniel F.
A1  - Kuiper, Rowan
A1  - Stephens, Owen W.
A1  - Bertsch, Uta
A1  - Broderick, Peter
A1  - Campo, Chiara
A1  - Einsele, Hermann
A1  - Gregory, Walter A.
A1  - Gullberg, Urban
A1  - Henrion, Marc
A1  - Hillengass, Jens
A1  - Hoffmann, Per
A1  - Jackson, Graham H.
A1  - Johnsson, Ellinor
A1  - Jöud, Magnus
A1  - Kristinsson, Sigurdur Y.
A1  - Lenhoff, Stig
A1  - Lenive, Oleg
A1  - Mellqvist, Ulf-Henrik
A1  - Migliorini, Gabriele
A1  - Nahi, Hareth
A1  - Nelander, Sven
A1  - Nickel, Jolanta
A1  - Nöthen, Markus M.
A1  - Rafnar, Thorunn
A1  - Ross, Fiona M.
A1  - da Silva Filho, Miguel Inacio
A1  - Swaminathan, Bhairavi
A1  - Thomsen, Hauke
A1  - Turesson, Ingemar
A1  - Vangsted, Annette
A1  - Vogel, Ulla
A1  - Waage, Anders
A1  - Walker, Brian A.
A1  - Wihlborg, Anna-Karin
A1  - Broyl, Annemiek
A1  - Davies, Faith E.
A1  - Thorsteinsdottir, Unnur
A1  - Langer, Christian
A1  - Hansson, Markus
A1  - Kaiser, Martin
A1  - Sonneveld, Pieter
A1  - Stefansson, Kari
A1  - Morgan, Gareth J.
A1  - Goldschmidt, Hartmut
A1  - Hemminki, Kari
A1  - Nilsson, Björn
A1  - Houlston, Richard S.
T1  - Genome-wide association study identifies multiple susceptibility loci for multiple myeloma
JF  - Nature Communications
N2  - Multiple myeloma (MM) is a plasma cell malignancy with a significant heritable basis. Genome-wide association studies have transformed our understanding of MM predisposition, but individual studies have had limited power to discover risk loci. Here we perform a meta-analysis of these GWAS, add a new GWAS and perform replication analyses resulting in 9,866 cases and 239,188 controls. We confirm all nine known risk loci and discover eight new loci at 6p22.3 (rs34229995, P=1.31 × 10−8), 6q21 (rs9372120, P=9.09 × 10−15), 7q36.1 (rs7781265, P=9.71 × 10−9), 8q24.21 (rs1948915, P=4.20 × 10−11), 9p21.3 (rs2811710, P=1.72 × 10−13), 10p12.1 (rs2790457, P=1.77 × 10−8), 16q23.1 (rs7193541, P=5.00 × 10−12) and 20q13.13 (rs6066835, P=1.36 × 10−13), which localize in or near to JARID2, ATG5, SMARCD3, CCAT1, CDKN2A, WAC, RFWD3 and PREX1. These findings provide additional support for a polygenic model of MM and insight into the biological basis of tumour development.
KW  - Cancer genetics
KW  - Genome-wide association studies
KW  - Myeloma
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165983
VL  - 7
ER  - 
TY  - JOUR
A1  - Novakova, Iveta
A1  - Subileau, Eva-Anne
A1  - Toegel, Stefan
A1  - Gruber, Daniela
A1  - Lachmann, Bodo
A1  - Urban, Ernst
A1  - Chesne, Christophe
A1  - Noe, Christian R.
A1  - Neuhaus, Winfried
T1  - Transport Rankings of Non-Steroidal Antiinflammatory Drugs across Blood-Brain Barrier In Vitro Models
JF  - PLoS ONE
N2  - The aim of this work was to conduct a comprehensive study about the transport properties of NSAIDs across the blood-brain barrier (BBB) in vitro. Transport studies with celecoxib, diclofenac, ibuprofen, meloxicam, piroxicam and tenoxicam were accomplished across Transwell models based on cell line PBMEC/C1-2, ECV304 or primary rat brain endothelial cells. Single as well as group substance studies were carried out. In group studies substance group compositions, transport medium and serum content were varied, transport inhibitors verapamil and probenecid were added. Resulted permeability coefficients were compared and normalized to internal standards diazepam and carboxyfluorescein. Transport rankings of NSAIDs across each model were obtained. Single substance studies showed similar rankings as corresponding group studies across PBMEC/C1-2 or ECV304 cell layers. Serum content, glioma conditioned medium and inhibitors probenecid and verapamil influenced resulted permeability significantly. Basic differences of transport properties of the investigated NSAIDs were similar comparing all three in vitro BBB models. Different substance combinations in the group studies and addition of probenecid and verapamil suggested that transporter proteins are involved in the transport of every tested NSAID. Results especially underlined the importance of same experimental conditions (transport medium, serum content, species origin, cell line) for proper data comparison.
KW  - NSAIDs
KW  - astrocytes
KW  - transport inhibition assay
KW  - drug-drug interactions
KW  - diazepam
KW  - permeability
KW  - glioma
KW  - scanning electron microscopy
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119992
VL  - 9
IS  - 1
ER  - 
TY  - THES
A1  - Urban, Christian
T1  - Design, Synthese und Untersuchung eines Membrantransporters für acetylierte Aminosäuren
T1  - Design, Synthesis and Investigation of a Membrane Transporter for Acetylated Amino Acids
N2  - Im Rahmen dieser Arbeit wurde ein synthetischer Membrantransporter für acetylierte Aminosäurecarboxylate entworfen und hergestellt. Als Bindungsstelle für die Carboxylate wurde das Guanidiniocarbonylpyrrol-Motiv von Schmuck verwendet. In den Seitenarm des Pyrrols wurde ein L-Valinamid-Rest eingebracht, um die Möglichkeit zu zusätzlichen Wasserstoffbrückenbindungen zu bieten und gegebenenfalls Substrat- und Enantioselektivität zu erreichen. Zur Herstellung der Löslichkeit in unpolaren Medien wie dem Inneren der Zellmembran musste eine lipophile Gruppe eingebracht werden. Als löslichkeitsvermittelnder Rest wurde Tris-(Dodecyloxy)phenylmethylen ausgewählt, das drei lange unpolare Alkylreste trägt. Zusammengenommen ergab sich so ein Rezeptor für Oxo-Anionen und speziell für Aminosäurecarboxylate mit erhöhter Löslichkeit in organischen Medien. Somit war die Fähigkeit zu Membrantransport gegeben. In Kraftfeldrechnungen erhielt man die vermutliche Struktur des Rezeptor-Substrat-Komplexes, der eine Kombination aus einer Salzbrücke, Wasserstoffbrückenbindungen und einer Stapelwechselwirkung von Guanidinum-Kation, Benzylgruppe und ggf. aromatischem Rest des Aminosäuresubstrates aufweist. Nach erfolgreicher Synthese wurde in Extraktionsexperimenten die Fähigkeit des Rezeptors erprobt, Aminosäurecarboxylate aus einer wässrigen in eine organische Phase aus zu überführen. Man erhielt das beste Extraktionsvermögen für Ac-Trp-OH, gefolgt von Ac Phe OH und Ac Tyr OH. Es wurde eine neue Formel aufgestellt, mit der aus den pKS-Werten der Substrate und den Extraktionsdaten mit und ohne Rezeptor die Bindungskonstanten der Rezeptor-Substrat-Komplexe berechnet werden konnten. Die Größe der Bindungkonstanten entsprach der Reihenfolge Trp > Tyr > Phe ~ Val mit den höchsten Bindungskonstanten für das Tryptophanderivat mit 1.5*10E4 1/M. Zur Bestätigung der Bindungskonstanten wurden ITC-Messungen durchgeführt. Es wurden Messungen des Rezeptors in Chloroform mit den tert-Butylammoniumsalzen der acetylierten Aminosäuren Phenylalanin, Tyrosin und Valin durchgeführt. Für die Werte von Enthalpie und Entropie konnten bei dieser Auswertung konsistente Werte ermittelt werden. Die höchsten Werte der Enthalpie erhielt man für das Tyrosinderivat mit 3.7*10E3 cal/mol, gefolgt vom Phenylalaninderivat mit 2.8*10E3 cal/mol und Valinderivat mit 1.3*10E3 cal/mol. Diese Abstufung entspricht dem Einfluss des aromatischen Restes, der durch die Stapelwechselwirkung mit dem Guanidinium-Kation die Bindungswärme erhöht und durch den damit verbundenen engeren Komplex den Wert für die Entropie senkt. Für die Evaluierung des Transportvermögens wurden U-Rohr-Versuche verschiedener Art durchgeführt. Es wurde ein Gradient von pH 6 in der Ausgangsphase auf pH 8 in der Zielphase eingesetzt, wodurch der Rezeptor an der Grenzfläche zur Zielphase deprotoniert wurde, was zu gerichtetetem Transport führte. Es ergaben sich recht starke Unterschiede für die Fluxwerte der einzelnen Substraten, die der Reihenfolge Val > Phe > Ala > Trp > Tyr folgten. Dabei wurde das Valinderivat um den Faktor 17 schneller als das Tyrosinderivat befördert, mit dem recht hohen Flux von 1.11*10E-6 mol/m2*s, was nahe an den höchsten literaturbekannten Wert für acetylierte Aminosäuren heranreicht. Durch Verwendung gleicher Substratkonzentrationen in Start- und Zielphase konnte aktiver Transport nachgewiesen werden, d.h. Transport gegen das Konzentrationsgefälle. Die Triebkraft des Transportes war der Gradient von pH 6 auf pH 8 zwischen Ausgangs- und Zielphase, der durch den Symport von Substrat und einem Proton ausgeglichen wurde. Bei einem kompetitiven Versuch mit einer Mischung der verschiedenen Substrate in der Ausgangsphase wurden veränderte Fluxwerte und Selektivitäten festgestellt. Die neue Reihenfolge der Transportgeschwindigkeit war nun Trp > Phe > Val > Tyr > Ala, wobei die Fluxwerte fast durchgehend niedriger waren als im Einzelversuch. Die Veränderung der Werte erschließt sich bei Vergleich mit den thermodynamischen Daten aus den Extraktionsexperimenten. Bei direkter Konkurrenz um den Rezeptor wurden diejenigen Substrate mit den höchsten Bindungskonstanten bevorzugt, unabhängig von ihrer Transportgeschwindigkeit. Die schwächer bindenden Substrate wurden aus dem Komplex verdrängt und wiesen deswegen niedrigere Transportwerte auf. Der kompetitive Versuch ist somit eine stärkere Abbildung der Bindungsstärke und entspricht eher der Situation in einer realen Zelle.
N2  - Within the scope of this work a new membrane carrier for acetylated amino acids was designed and synthesized. For the binding site of the carboxylate the guanidinio-carbonylpyrrole motif by Schmuck was selected. In the pyrrole’s side chain an L-valinamide residue was introduced, to allow for additional hydrogen bonding and potentially achieve substrate- and enantioselectivity. For solubility in nonpolar media such as the inner part of the cell membrane a lipophilic group had to be introduced. Tris-(dodecyloxy)-phenylmethylene, which bears three long, nonpolar alkyl chains, was selected to procure the desired solubility. All in all this yielded a receptor for oxo-anions and especially for amino acid carboxylates with increased solubility in organic media. This design resulted in the ability for membrane transport. In force field calculations the probable structure of the receptor-substrate-complex was obtained. It showed a combination of a salt bridge, hydrogen bonds and pi-stacking between the guanidinium cation, the benzyl group and, if applicable, the amino acid’s aromatic residue. After the successful synthesis, extraction experiments were carried out to test the receptor’s ability to transfer amino acid carboxylates from an aqueous into an organic phase. The best extractability was attained for Ac-Trp-OH, followed by Ac-Phe-OH and Ac-Tyr-OH. A new equation was established to calculate the binding constants of the receptor-substrate-complexes with the known pKS-values of the substrates and the extraction data with and without receptor. The values of the binding constants followed the order Trp > Tyr > Phe ~ Val with the highest values for the tryptophane derivative with 1.5*10E4 1/M. To confirm the binding constants, ITC experiments were conducted. Measurements of the receptor in chloroform with the tert-butylammonium salts of the acetylated amino acids phenylalanine, tyrosine and valine were conducted.For the enthalpy and entropy consistent values could be determined. These were 3.7*10E3 cal/mol for the tyrosine derivative, 2.8*10E3 cal/mol for the phenylalanine derivative and 1.3*10E3 cal/mol for the valine derivative. This incrementation complies with the influence of the aromatic residue, which increases the binding heat by the pi-stacking and decreases the value of the entropy because of the resulting tighter complex. For the evaluation of the transport capabilities various U-tube experiments were conducted. A gradient from pH 6 in the source phase to pH 8 in the target phase was employed, which led to deprotonation of the receptor near the interface to the target phase, resulting in directed transport. There were quite strong differences for the substrates’ flux values, which followed the order of Val > Phe > Ala > Trp > Tyr. The valine derivative was transported 17 times faster than the tyrosine derivative, with a quite high flux of 1.11*10E-6 mol/m2*s. This is close to the highest literature-known value for acetylated amino acids. By employing analogous substrate concentrations in the source and target phase, active transport, that is transport against the concentration gradient, could be achieved. The driving force of the transport was the gradient from pH 6 to pH 8 between the source and target phase, which was diminished by the symport of substrate and a proton. In a competitive experiment with a mixture of the various substrates in the source phase different values for flux and selectivity were found. The new order of the transport velocities was now Trp > Phe > Val > Tyr > Ala. Nearly all of the flux values were lower than before. The change of the values can be explained by the comparison with the thermodynamic data from the extraction experiments. With direct competition for the receptor, the substrates with higher binding constants were preferred, independent of their transport velocity. The substrates with weaker binding were expulsed from the complex and now showed lower transport values. The competitive transport experiment is therefor a better depiction of the binding strength and comes closer to the situation in a real cell.
KW  - Molekulare Erkennung
KW  - Guanidiniumverbindungen
KW  - Aminosäurentransport
KW  - Flüssig-Flüssig-Extraktion
KW  - Membrantransport
KW  - Supramolekulare Chemie
KW  - Organische Synthese
KW  - Pyrrolderivate
KW  - Naturstoffchemie
KW  - Adiabatische Kalorimetrie
KW  - UV-VIS-Spektroskopi
KW  - Aktiver Transport
KW  - Molecular Recognition
KW  - Guanidinium Cations
KW  - Amino Acid Transport
KW  - Amino Acid Extraction
KW  - Membrane Carrier
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-38094
ER  - 
TY  - JOUR
A1  - Karastaneva, Anna
A1  - Lanz, Sofia
A1  - Wawer, Angela
A1  - Behrends, Uta
A1  - Schindler, Detlev
A1  - Dietrich, Ralf
A1  - Burdach, Stefan
A1  - Urban, Christian
A1  - Benesch, Martin
A1  - Seidel, Markus G.
T1  - Immune thrombocytopenia in two unrelated Fanconi anemia patients - a mere coincidence?
JF  - Frontiers in Pediatrics
N2  - Thrombocytopenia and pancytopenia, occurring in patients with Fanconi anemia (FA), are interpreted either as progression to bone marrow failure or as developing myelodysplasia. On the other hand, immune thrombocytopenia (ITP) represents an acquired and often self-limiting benign hematologic disorder, associated with peripheral, immune-mediated, platelet destruction requiring different management modalities than those used in congenital bone marrow failure syndromes, including FA. Here, we describe the clinical course of two independent FA patients with atypical – namely immune – thrombocytopenia. While in one patient belonging to complementation group FA-A, the ITP started at 17 months of age and showed a chronically persisting course with severe purpura, responding well to intravenous immunoglobulins (IVIG) and later also danazol, a synthetic androgen, the other patient (of complementation group FA-D2) had a self-limiting course that resolved after one administration of IVIG. No cytogenetic aberrations or bone marrow abnormalities other than FA-typical mild dysplasia were detected. Our data show that acute and chronic ITP may occur in FA patients and impose individual diagnostic and therapeutic challenges in this rare congenital bone marrow failure/tumor predisposition syndrome. The management and a potential context of immune pathogenesis with the underlying marrow disorder are discussed.
KW  - immune thrombocytopenia
KW  - bone marrow failure syndrome
KW  - Evans syndrome
KW  - danazol
KW  - FANCA
KW  - FANCD2
KW  - Fanconi anemia
KW  - DNA repair defect
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149837
VL  - 3
IS  - 50
ER  - 
TY  - JOUR
A1  - Assfalg, Volker
A1  - Selig, Katharina
A1  - Tolksdorf, Johanna
A1  - van Meel, Marieke
A1  - de Vries, Erwin
A1  - Ramsoebhag, Anne‐Marie
A1  - Rahmel, Axel
A1  - Renders, Lutz
A1  - Novotny, Alexander
A1  - Matevossian, Edouard
A1  - Schneeberger, Stefan
A1  - Rosenkranz, Alexander R.
A1  - Berlakovich, Gabriela
A1  - Ysebaert, Dirk
A1  - Knops, Noël
A1  - Kuypers, Dirk
A1  - Weekers, Laurent
A1  - Muehlfeld, Anja
A1  - Rump, Lars‐Christian
A1  - Hauser, Ingeborg
A1  - Pisarski, Przemyslaw
A1  - Weimer, Rolf
A1  - Fornara, Paolo
A1  - Fischer, Lutz
A1  - Kliem, Volker
A1  - Sester, Urban
A1  - Stippel, Dirk
A1  - Arns, Wolfgang
A1  - Hau, Hans‐Michael
A1  - Nitschke, Martin
A1  - Hoyer, Joachim
A1  - Thorban, Stefan
A1  - Weinmann‐Menke, Julia
A1  - Heller, Katharina
A1  - Banas, Bernhard
A1  - Schwenger, Vedat
A1  - Nadalin, Silvio
A1  - Lopau, Kai
A1  - Hüser, Norbert
A1  - Heemann, Uwe
T1  - Repeated kidney re‐transplantation—the Eurotransplant experience: a retrospective multicenter outcome analysis
JF  - Transplant International
N2  - In Eurotransplant kidney allocation system (ETKAS), candidates can be considered unlimitedly for repeated re‐transplantation. Data on outcome and benefit are indeterminate. We performed a retrospective 15‐year patient and graft outcome data analysis from 1464 recipients of a third or fourth or higher sequential deceased donor renal transplantation (DDRT) from 42 transplant centers. Repeated re‐DDRT recipients were younger (mean 43.0 vs. 50.2 years) compared to first DDRT recipients. They received grafts with more favorable HLA matches (89.0% vs. 84.5%) but thereby no statistically significant improvement of patient and graft outcome was found as comparatively demonstrated in 1st DDRT. In the multivariate modeling accounting for confounding factors, mortality and graft loss after 3rd and ≥4th DDRT (P < 0.001 each) and death with functioning graft (DwFG) after 3rd DDRT (P = 0.001) were higher as compared to 1st DDRT. The incidence of primary nonfunction (PNF) was also significantly higher in re‐DDRT (12.7%) than in 1st DDRT (7.1%; P < 0.001). Facing organ shortage, increasing waiting time, and considerable mortality on dialysis, we question the current policy of repeated re‐DDRT. The data from this survey propose better HLA matching in first DDRT and second DDRT and careful selection of candidates, especially for ≥4th DDRT.
KW  - allocation
KW  - child
KW  - fourth
KW  - graft
KW  - kidney
KW  - loss
KW  - repeated
KW  - re‐transplantation
KW  - survival
KW  - third
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214161
VL  - 33
IS  - 6
SP  - 617
EP  - 631
ER  - 
TY  - JOUR
A1  - Gentzsch, Christian
A1  - Chen, Xinyu
A1  - Spatz, Philipp
A1  - Košak, Urban
A1  - Knez, Damijan
A1  - Nose, Naoko
A1  - Gobec, Stanislav
A1  - Higuchi, Takahiro
A1  - Decker, Michael
T1  - Synthesis and Initial Characterization of a Reversible, Selective \(^{18}\)F-Labeled Radiotracer for Human Butyrylcholinesterase
JF  - Molecular Imaging and Biology
N2  - Purpose
A neuropathological hallmark of Alzheimer's disease (AD) is the presence of amyloid-β (Aβ) plaques in the brain, which are observed in a significant number of cognitively normal, older adults as well. In AD, butyrylcholinesterase (BChE) becomes associated with A\(_{β}\) aggregates, making it a promising target for imaging probes to support diagnosis of AD. In this study, we present the synthesis, radiochemistry, in vitro and preliminary ex and in vivo investigations of a selective, reversible BChE inhibitor as PET-tracer for evaluation as an AD diagnostic.
Procedures
Radiolabeling of the inhibitor was achieved by fluorination of a respective tosylated precursor using K[\(^{18}\)F]. IC\(_{50}\) values of the fluorinated compound were obtained in a colorimetric assay using recombinant, human (h) BChE. Dissociation constants were determined by measuring hBChE activity in the presence of different concentrations of inhibitor.
Results
Radiofluorination of the tosylate precursor gave the desired radiotracer in an average radiochemical yield of 20 ± 3 %. Identity and > 95.5 % radiochemical purity were confirmed by HPLC and TLC autoradiography. The inhibitory potency determined in Ellman's assay gave an IC\(_{50}\) value of 118.3 ± 19.6 nM. Dissociation constants measured in kinetic experiments revealed lower affinity of the inhibitor for binding to the acylated enzyme (K2 = 68.0 nM) in comparison to the free enzyme (K\(_{1}\) = 32.9 nM).
Conclusions
The reversibly acting, selective radiotracer is synthetically easily accessible and retains promising activity and binding potential on hBChE. Radiosynthesis with \(^{18}\)F labeling of tosylates was feasible in a reasonable time frame and good radiochemical yield.
KW  - Alzheimer’s disease
KW  - amyloid-β (Aβ)
KW  - butyrylcholinesterase
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-269870
SN  - 1860-2002
VL  - 23
IS  - 4
ER  - 
TY  - JOUR
A1  - Urban, Lara
A1  - Remmele, Christian W.
A1  - Dittrich, Marcus
A1  - Schwarz, Roland F.
A1  - Müller, Tobias
T1  - covRNA: discovering covariate associations in large-scale gene expression data
JF  - BMC Reserach Notes
N2  - Objective
The biological interpretation of gene expression measurements is a challenging task. While ordination methods are routinely used to identify clusters of samples or co-expressed genes, these methods do not take sample or gene annotations into account. We aim to provide a tool that allows users of all backgrounds to assess and visualize the intrinsic correlation structure of complex annotated gene expression data and discover the covariates that jointly affect expression patterns.

Results
The Bioconductor package covRNA provides a convenient and fast interface for testing and visualizing complex relationships between sample and gene covariates mediated by gene expression data in an entirely unsupervised setting. The relationships between sample and gene covariates are tested by statistical permutation tests and visualized by ordination. The methods are inspired by the fourthcorner and RLQ analyses used in ecological research for the analysis of species abundance data, that we modified to make them suitable for the distributional characteristics of both, RNA-Seq read counts and microarray intensities, and to provide a high-performance parallelized implementation for the analysis of large-scale gene expression data on multi-core computational systems. CovRNA provides additional modules for unsupervised gene filtering and plotting functions to ensure a smooth and coherent analysis workflow.
KW  - Multivariate analysis
KW  - Fourthcorner analysis
KW  - RLQ analysis
KW  - Transcriptomics
KW  - High-throughput data
KW  - Visualization
KW  - Ordination methods
KW  - RNA-Seq analysis
KW  - Microarray analysis
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229258
VL  - 13
ER  -