751 results on '"Stadler H"'
Search Results
302. Spontaneous partitioning of the Ni+C60 thin film grown at RT
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Vacik, J., Lavrentiev, V., Hnatowicz, V., Vorlicek, V., Yamamoto, S., and Stadler, H.
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METALLIC films , *NICKEL compounds , *PATTERN formation (Physical sciences) , *PHASE partition , *FULLERENES , *METALLIC composites , *MAGNETIC domain , *FERROMAGNETIC materials , *THERMODYNAMICS - Abstract
Abstract: We report on the pattern formation in the thin film of the Ni+C60 mixture deposited on the MgO(001) substrate at room temperature (RT). Using magnetic force microscopy a periodic array of the magnetic domains has been revealed. The domains reflect hidden partitioning of the Ni+C60 film (i.e., separated Ni- and C60-rich zones) that has not been observed by other applied methods. The effect indicates that even at RT, spontaneous separation of the Ni and C60 phases may set in during the growth of the hybrid film. Thermal annealing (for 1h at 500°C) leads to dramatic rearrangement of the Ni+C60 structure which (consequently) also results in the loss of the magnetic domain system. This phenomenon points out the thermodynamic instability of the as-prepared hybrid film that can (at elevated temperatures) trigger the process of the Ni and C60 phase separation. [Copyright &y& Elsevier]
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- 2009
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303. Detailed investigation of a pulverized fuel swirl flame in CO2/O2 atmosphere
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Toporov, D., Bocian, P., Heil, P., Kellermann, A., Stadler, H., Tschunko, S., Förster, M., and Kneer, R.
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FLAME , *SIMULATION methods & models , *COMBUSTION , *CARBON dioxide , *MASS transfer , *NUMERICAL analysis , *AERODYNAMICS - Abstract
Abstract: A novel approach to oxycoal flame stabilization has been developed at the Institute of Heat and Mass Transfer at RWTH Aachen University [D. Toporov, M. Förster, R. Kneer, in: Third Int. Conf. on Clean Coal Technologies for Our Future, Cagliari, Sardinia, Italy, 15–17 May 2007]. The swirl burner design and its operating conditions have been adjusted in order to enforce CO formation thus stabilizing the flame and obtaining a full burnout at levels of O2 content in the O2/CO2 mixture similar to those in air. The paper presents results of detailed numerical and experimental investigations of a stable oxy-fired pulverized coal swirl flame (type-2) obtained with a 21 vol% O2 concentration. The combustion tests were performed in a vertical pilot-scale furnace (100 kWth) in the framework of the OXYCOAL-AC research project aiming to develop a membrane-based oxyfuel process. The experimental results concerning gas velocities, gas and particle temperatures, and gas compositions are presented and discussed, focusing on the underlying mechanisms as well as on the aerodynamics of the oxycoal flame. A comparison between measurements and simulations has shown the validity of the numerical method used. The reported data set can be used for validation of numerical models developed for prediction of oxyfuel combustion. [Copyright &y& Elsevier]
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- 2008
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304. Quantitative microbial faecal source tracking with sampling guided by hydrological catchment dynamics.
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Reischer, G. H., Haider, J. M., Sommer, R., Stadler, H., Keiblinger, K. M., Hornek, R., Zerobin, W., Mach, R. L., and Farnleitner, A. H.
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FECES , *WATERSHEDS , *WATER quality management , *FLOODS , *PUBLIC health , *AQUATIC sciences , *MICROBIAL ecology - Abstract
The impairment of water quality by faecal pollution is a global public health concern. Microbial source tracking methods help to identify faecal sources but the few recent quantitative microbial source tracking applications disregarded catchment hydrology and pollution dynamics. This quantitative microbial source tracking study, conducted in a large karstic spring catchment potentially influenced by humans and ruminant animals, was based on a tiered sampling approach: a 31-month water quality monitoring (Monitoring) covering seasonal hydrological dynamics and an investigation of flood events (Events) as periods of the strongest pollution. The detection of a ruminant-specific and a human-specific faecal Bacteroidetes marker by quantitative real-time PCR was complemented by standard microbiological and on-line hydrological parameters. Both quantitative microbial source tracking markers were detected in spring water during Monitoring and Events, with preponderance of the ruminant-specific marker. Applying multiparametric analysis of all data allowed linking the ruminant-specific marker to general faecal pollution indicators, especially during Events. Up to 80% of the variation of faecal indicator levels during Events could be explained by ruminant-specific marker levels proving the dominance of ruminant faecal sources in the catchment. Furthermore, soil was ruled out as a source of quantitative microbial source tracking markers. This study demonstrates the applicability of quantitative microbial source tracking methods and highlights the prerequisite of considering hydrological catchment dynamics in source tracking study design. [ABSTRACT FROM AUTHOR]
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- 2008
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305. Elucidation, Quantitative Refinement, and in Vivo Utilization of the HOXA13 DNA Binding Site.
- Author
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Knosp, Wendy M., Saneyoshi, Chie, Siming Shou, Bächinger, Hans Peter, and Scott^Stadler, H.
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GENETIC mutation , *GENITOURINARY organs , *GENE expression , *PHOSPHORYLATION , *GENETIC regulation - Abstract
Mutations in Hoxa13 cause malformations of the appendicular skeleton and genitourinary tract, including digit loss, syndactyly, and hypospadias. To determine the molecular basis for these defects, the DNA sequences bound by HOXA13 were empirically determined, revealing a novel high affinity binding site. Correlating the utilization of this high affinity binding site with genes exhibiting perturbed expression in Hoxa13 mutant limbs, we identified that HOXA13 suppresses the expression of the BMP antagonist, Sostdc1. In the absence of HOXA13 function, Sostdc1 is ectopically expressed in the distal limb, causing reduced expression of BMP-activated genes and decreased SMAD phosphorylation. Limb chromatin immunoprecipitation revealed HOXA13 binding at its high affinity site in two conserved Sostdc1 regulatory sites in vivo. In vitro, HOXA13 represses gene expression through the Sostdc1 high affinity binding sites in a dosage-dependent manner. Together, these findings confirm that the high affinity HOXA13 binding site deduced by quantitative analyses is used in vivo to facilitate HOXA13 target gene regulation, providing a critical advance toward understanding the molecular basis for defects associated with the loss of HOXA13 function. [ABSTRACT FROM AUTHOR]
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- 2007
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306. Genetic basis for an evolutionary shift from ancestral preaxial to postaxial limb polarity in non-urodele vertebrates.
- Author
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Trofka, Anna, Huang, Bau-Lin, Zhu, Jianjian, Heinz, William F., Magidson, Valentin, Shibata, Yuki, Shi, Yun-Bo, Tarchini, Basile, Stadler, H. Scott, Kabangu, Mirindi, Al Haj Baddar, Nour W., Voss, S. Randal, and Mackem, Susan
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AXOLOTLS , *FIBULA , *DELETION mutation , *AMPHIBIANS , *ADULTS , *SALAMANDERS , *MICE , *VERTEBRATES - Abstract
In most tetrapod vertebrates, limb skeletal progenitors condense with postaxial dominance. Posterior elements (such as ulna and fibula) appear prior to their anterior counterparts (radius and tibia), followed by digit-appearance order with continuing postaxial polarity. The only exceptions are urodele amphibians (salamanders), whose limb elements develop with preaxial polarity and who are also notable for their unique ability to regenerate complete limbs as adults. The mechanistic basis for this preaxial dominance has remained an enigma and has even been proposed to relate to the acquisition of novel genes involved in regeneration. However, recent fossil evidence suggests that preaxial polarity represents an ancestral rather than derived state. Here, we report that 5′ Hoxd (Hoxd11-d13) gene deletion in mouse is atavistic and uncovers an underlying preaxial polarity in mammalian limb formation. We demonstrate this shift from postaxial to preaxial dominance in mouse results from excess Gli3 repressor (Gli3R) activity due to the loss of 5′Hoxd-Gli3 antagonism and is associated with cell-cycle changes promoting precocious cell-cycle exit in the anterior limb bud. We further show that Gli3 knockdown in axolotl results in a shift to postaxial dominant limb skeleton formation, as well as expanded paddle-shaped limb-bud morphology and ensuing polydactyly. Evolutionary changes in Gli3R activity level, which also played a key role in the fin-to-limb transition, appear to be fundamental to the shift from preaxial to postaxial polarity in formation of the tetrapod limb skeleton. [Display omitted] • Gli3 repressor (Gli3R) activity level governs tetrapod limb axis formation polarity • 5′Hoxd-Gli3 balance modulates cell-cycle exit to determine mouse limb axis polarity • Alternating A-P digit appearance in mammals is linked to primary limb axis polarity • Axolotl Gli3 knockdown shifts the ancestral preaxial dominance to postaxial Uniquely in salamanders, the tetrapod primary limb axis forms with ancestral preaxial dominance, but the underlying basis is unknown. Here, Trofka et al. show Gli3 has a central role; mice with elevated Gli3 repressor activity revert to preaxial dominance. Conversely, Gli3 knockdown shifts the axolotl limb axis from preaxial to postaxial polarity. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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307. ATTENCATORS FOR HIGH FREQUENCY PULSES
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Stadler, H
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- 1962
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308. ABSORPTION OF POSITIVE PIONS BY DEUTERIUM AT 76 AND 94 MEV
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Stadler, H
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- 1954
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309. Correction: AFM-IR investigation of thin PECVD SiO x films on a polypropylene substrate in the surface-sensitive mode.
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Müller H, Stadler H, de Los Arcos T, Keller A, and Grundmeier G
- Abstract
[This corrects the article DOI: 10.3762/bjnano.15.51.]., (Copyright © 2025, Müller et al.)
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- 2025
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310. Determination diabetes mellitus disease markers in tear fluid by photothermal AFM-IR analysis.
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Kondrakhova D, Unger M, Stadler H, Zakuťanská K, Tomašovičová N, Tomečková V, Horák J, Kimákova T, and Komanický V
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- Humans, Spectroscopy, Fourier Transform Infrared methods, Male, Muramidase metabolism, Muramidase analysis, Female, Middle Aged, Adult, Glucose, Tears chemistry, Tears metabolism, Microscopy, Atomic Force, Biomarkers, Diabetes Mellitus pathology, Diabetes Mellitus metabolism
- Abstract
The tear fluids from three healthy individuals and three patients with diabetes mellitus were examined using atomic force microscopy-infrared spectroscopy (AFM-IR) and Fourier transform infrared spectroscopy (FTIR). The dried tear samples showed different surface morphologies: the control sample had a dense network of heart-shaped dendrites, while the diabetic sample had fern-shaped dendrites. By using the AFM-IR technique we identified spatial distribution of constituents, indicating how diabetes affects the structural characteristics of dried tears. FTIR showed that the dendritic structures gradually disappeared over time due to glucose-induced lysozyme damage. The tear fluid from diabetes mellitus patients has a higher concentration of glucose, which accelerates the breakdown of lysozyme and, as a result, the quick loss of the dendritic structure. Our study shows that analysis of dry tear fluid can be promising technique for the detection of glycated proteins that reveal long lasting hyperglycemia and diabetes mellitus., Competing Interests: Declaration of competing interest The authors confirm that there are no conflicts of interest., (Copyright © 2025 Elsevier Inc. All rights reserved.)
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- 2025
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311. AFM-IR investigation of thin PECVD SiO x films on a polypropylene substrate in the surface-sensitive mode.
- Author
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Müller H, Stadler H, de Los Arcos T, Keller A, and Grundmeier G
- Abstract
Thin silicon oxide films deposited on a polypropylene substrate by plasma-enhanced chemical vapor deposition were investigated using atomic force microscopy-based infrared (AFM-IR) nanospectroscopy in contact and surface-sensitive mode. The focus of this work is the comparison of the different measurement methods (i.e., contact mode and surface-sensitive mode) with respect to the chemical surface sensitivity. The use of the surface-sensitive mode in AFM-IR shows an enormous improvement for the analysis of thin films on the IR-active substrate. As a result, in this mode, the signal of the substrate material could be significantly reduced. Even layers that are so thin that they could hardly be measured in the contact mode can be analyzed with the surface-sensitive mode., (Copyright © 2024, Müller et al.)
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- 2024
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312. Effectiveness of Neuropediatric Inpatient Rehabilitation.
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Stadler H, Müller K, Kurlemann G, and Lendt M
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- Adolescent, Humans, Female, Child, Male, Retrospective Studies, Inpatients, Treatment Outcome, Brain Injuries, Stroke
- Abstract
Aim: Inpatient rehabilitation plays an important role in treating neurological diseases in children and adolescents. However, there is a lack of current research concerning this matter. This retrospective study aims to analyze the effectiveness of neuropediatric inpatient rehabilitation, to identify influencing factors, and to examine the importance of inpatient rehabilitation programs., Methods: We reviewed medical records of patients, diagnosed with cerebral palsy, traumatic brain injury (TBI), or stroke who had an inpatient rehabilitation at the Department of Neuropediatrics of St. Mauritius Therapieklinik in Meerbusch from 2012 to 2019. The patients received several units of different therapies such as motor and cognitive rehabilitation or speech therapy per day, depending on their individual needs and aims. Rehabilitation outcome was assessed by comparing Gross Motor Function Measure-88 and Pediatric Evaluation of Disability Inventory admission and discharge scores. Influences of sex, age, length of stay (LOS), and admission score were analyzed., Results: A total of 738 patients with a mean age of 9.2 (± 5.1) years and a mean LOS of 53.8 (± 33.7) days were included; 38.5% were female. Patients, regardless of their diagnosis, sex, or age, demonstrated highly significant and meaningful improvements of self-care, mobility, and social function during inpatient rehabilitation. Especially, the group of patients with TBI and stroke could approximate their skills substantially to the ones of healthy peers. A longer LOS correlated significantly with greater improvement of skills., Interpretation: This is a current study, supporting the effectiveness of neuropediatric inpatient rehabilitation and affirming its value in treating neurological diseases in children and adolescents., Competing Interests: None declared., (Thieme. All rights reserved.)
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- 2024
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313. Digits in a dish: An in vitro system to assess the molecular genetics of hand/foot development at single-cell resolution.
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Fuiten AM, Yoshimoto Y, Shukunami C, and Stadler HS
- Abstract
In vitro models allow for the study of developmental processes outside of the embryo. To gain access to the cells mediating digit and joint development, we identified a unique property of undifferentiated mesenchyme isolated from the distal early autopod to autonomously re-assemble forming multiple autopod structures including: digits, interdigital tissues, joints, muscles and tendons. Single-cell transcriptomic analysis of these developing structures revealed distinct cell clusters that express canonical markers of distal limb development including: Col2a1 , Col10a1 , and Sp7 (phalanx formation), Thbs2 and Col1a1 (perichondrium), Gdf5 , Wnt5a , and Jun (joint interzone), Aldh1a2 and Msx1 (interdigital tissues), Myod1 (muscle progenitors), Prg4 (articular perichondrium/articular cartilage), and Scx and Tnmd (tenocytes/tendons). Analysis of the gene expression patterns for these signature genes indicates that developmental timing and tissue-specific localization were also recapitulated in a manner similar to the initiation and maturation of the developing murine autopod. Finally, the in vitro digit system also recapitulates congenital malformations associated with genetic mutations as in vitro cultures of Hoxa13 mutant mesenchyme produced defects present in Hoxa13 mutant autopods including digit fusions, reduced phalangeal segment numbers, and poor mesenchymal condensation. These findings demonstrate the robustness of the in vitro digit system to recapitulate digit and joint development. As an in vitro model of murine digit and joint development, this innovative system will provide access to the developing limb tissues facilitating studies to discern how digit and articular joint formation is initiated and how undifferentiated mesenchyme is patterned to establish individual digit morphologies. The in vitro digit system also provides a platform to rapidly evaluate treatments aimed at stimulating the repair or regeneration of mammalian digits impacted by congenital malformation, injury, or disease., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Fuiten, Yoshimoto, Shukunami and Stadler.)
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- 2023
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314. Enhanced Simulation of Infrared Heating of Thermoplastic Composites Prior to Forming under Consideration of Anisotropic Thermal Conductivity and Deconsolidation by Means of Novel Physical Material Models.
- Author
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Längauer M, Zitzenbacher G, Stadler H, and Hochenauer C
- Abstract
In recent years, thermoplastic composites have found their place in large business sectors and are in direct rivalry to thermoset matrix composites. In order to ensure efficient and lean processes, process modeling gains ever-growing attention. This work shows the computational fluid dynamics (CFD)-modeling of a typical heating step in a thermoforming process of a thermoplastic composite sheet. When heating thermoplastic composites, the heat conduction proceeds anisotropic, and the sheets are subject to thermal deconsolidation when heated above the melting temperature of the polymer matrix adding to the anisotropic effect. These effects are neglected in known process models and this study shows the first successful attempt at introducing them into CFD-modeling of the heating of thermoplastic composite sheets. Thus, the simulation requires temperature dependent values for the anisotropic thermal conductivity and the coefficient of linear thermal expansion, which are calculated with novel physical models which were developed solely for this cause. This alters the behavior of an isotropic CFD-model and allows the successful validation via laboratory experiments using glass fiber reinforced polypropylene (PP/GF) sheets with embedded thermocouples to check the internal temperature distribution when the sheet is heated to the designated forming temperature in a composite thermoforming press. The incorporation of this newly developed process model reduces the error in the core temperature prediction from close to 70 °C to 3 °C at the forming temperature.
- Published
- 2022
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315. Author Correction: High resolution nanoscale chemical analysis of bitumen surface microstructures.
- Author
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Koyun AN, Zakel J, Kayser S, Stadler H, Keutsch FN, and Grothe H
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- 2021
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316. High resolution nanoscale chemical analysis of bitumen surface microstructures.
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Koyun AN, Zakel J, Kayser S, Stadler H, Keutsch FN, and Grothe H
- Abstract
Surface microstructures of bitumen are key sites in atmospheric photo-oxidation leading to changes in the mechanical properties and finally resulting in cracking and rutting of the material. Investigations at the nanoscale remain challenging. Conventional combination of optical microscopy and spectroscopy cannot resolve the submicrostructures due to the Abbe restriction. For the first time, we report here respective surface domains, namely catana, peri and para phases, correlated to distinct molecules using combinations of atomic force microscopy with infrared spectroscopy and with correlative time of flight-secondary ion mass spectrometry. Chemical heterogeneities on the surface lead to selective oxidation due to their varying susceptibility to photo-oxidation. It was found, that highly oxidized compounds, are preferentially situated in the para phase, which are mainly asphaltenes, emphasising their high oxidizability. This is an impressive example how chemical visualization allows elucidation of the submicrostructures and explains their response to reactive oxygen species from the atmosphere.
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- 2021
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317. Multicomponent Covalent Chemical Patterning of Graphene.
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Rodríguez González MC, Leonhardt A, Stadler H, Eyley S, Thielemans W, De Gendt S, Mali KS, and De Feyter S
- Abstract
The chemical patterning of graphene is being pursued tenaciously due to exciting possibilities in electronics, catalysis, sensing, and photonics. Despite the intense efforts, spatially controlled, multifunctional covalent patterning of graphene has not been achieved. The lack of control originates from the inherently poor reactivity of the basal plane of graphene, which necessitates the use of harsh chemistries. Here, we demonstrate spatially resolved multicomponent covalent chemical patterning of single layer graphene using a facile and efficient method. Three different functional groups could be covalently attached to the basal plane in dense, well-defined patterns using a combination of lithography and a self-limiting variant of diazonium chemistry requiring no need for graphene activation. The layer thickness of the covalent films could be controlled down to 1 nm. This work provides a solid foundation for the fabrication of chemically patterned multifunctional graphene interfaces for device applications.
- Published
- 2021
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318. HOXA13 in etiology and oncogenic potential of Barrett's esophagus.
- Author
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Janmaat VT, Nesteruk K, Spaander MCW, Verhaar AP, Yu B, Silva RA, Phillips WA, Magierowski M, van de Winkel A, Stadler HS, Sandoval-Guzmán T, van der Laan LJW, Kuipers EJ, Smits R, Bruno MJ, Fuhler GM, Clemons NJ, and Peppelenbosch MP
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- Adult, Animals, Barrett Esophagus metabolism, Gastrointestinal Neoplasms genetics, Gastrointestinal Neoplasms metabolism, Gastrointestinal Tract metabolism, Gene Expression Profiling methods, Gene Expression Regulation, Homeodomain Proteins metabolism, Humans, Mice, Inbred C57BL, Mice, Knockout, Mice, Transgenic, Multigene Family genetics, RNA-Seq methods, Mice, Barrett Esophagus genetics, Carcinogenesis genetics, Homeodomain Proteins genetics, Oncogenes genetics
- Abstract
Barrett's esophagus in gastrointestinal reflux patients constitutes a columnar epithelium with distal characteristics, prone to progress to esophageal adenocarcinoma. HOX genes are known mediators of position-dependent morphology. Here we show HOX collinearity in the adult gut while Barrett's esophagus shows high HOXA13 expression in stem cells and their progeny. HOXA13 overexpression appears sufficient to explain both the phenotype (through downregulation of the epidermal differentiation complex) and the oncogenic potential of Barrett's esophagus. Intriguingly, employing a mouse model that contains a reporter coupled to the HOXA13 promotor we identify single HOXA13-positive cells distally from the physiological esophagus, which is mirrored in human physiology, but increased in Barrett's esophagus. Additionally, we observe that HOXA13 expression confers a competitive advantage to cells. We thus propose that Barrett's esophagus and associated esophageal adenocarcinoma is the consequence of expansion of this gastro-esophageal HOXA13-expressing compartment following epithelial injury.
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- 2021
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319. Hungarian validation of the Buss-Perry Aggression Questionnaire-Is the short form more adequate?
- Author
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Zimonyi S, Kasos K, Halmai Z, Csirmaz L, Stadler H, Rózsa S, Szekely A, and Kotyuk E
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- Factor Analysis, Statistical, Humans, Hungary, Surveys and Questionnaires, Aggression, Universities
- Abstract
Objective: We aim to provide a publicly available Hungarian version of the BPAQ; compare the BPAQ factors to other personality traits; and compare both the original BPAQ factor structure provided by Buss and Perry (J. Pers. Soc. Psychol., 63, 1992, 452), the revised BPAQ-SF factor structure by Bryant and Smith (J. Res. Pers., 35, 2001, 138), and the BAQ by Webster et al. (Aggress. Behav., 40, 2014, 120)., Methods: The validation of the Hungarian version of the BPAQ was carried out on a Hungarian university sample (N = 841). There were three main focuses of data analysis: descriptive statistics, correlations, and confirmatory factor analyses., Results: CFA-related statistics showed an adequate fit for the BPAQ 4 factors; however, contrary to prior validations of BPAQ, we were not able to clearly define the verbal aggression factor. We found that the shorter form of the BPAQ has a better model fit on our sample than the original form, while the model fit of the BAQ was in-between these. BPAQ scales showed low to moderate relationship with the Barratt Impulsivity Scale and Hospital Anxiety and Depression Scale., Conclusion: Both the BPAQ and the BPAQ-SF, also the BAQ provide acceptable model fitting on a Hungarian sample of university students. While most of BPAQ items provided adequate loadings on their hypothesized factors, two items (21 and 27) did not. We argue this is the result of conceptual inaccuracy of the original items., (© 2021 The Authors. Brain and Behavior published by Wiley Periodicals LLC.)
- Published
- 2021
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320. Handling "war graves": The current situation in Austria.
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Hausmair B, Theune C, and Stadler H
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- Archaeology, Austria, Burial, History, 20th Century, Holocaust history, Humans, Military Personnel history, World War I, World War II, Body Remains, Exhumation, Forensic Anthropology methods
- Abstract
The Second Republic of Austria was established after the Second World War. As a former part of the Austro-Hungarian Monarchy and subsequently Nazi Germany, its history is strongly shaped by two world wars and the deaths of millions of people. The handling of human remains and graves of victims of National Socialist terror, members of the armed forces of nations participating in the world wars as well as civilian casualties that are located on today's federal territory, has been regulated by law since 1948. The responsibility officially lies with the Federal Ministry of the Interior / Department for War Graves Services. In practice, various institutions and interest groups have been involved in the identification and maintenance of so-called "war graves" and the recovery of human remains. This article aims to provide a brief outline of the current legal situation in Austria and discusses varying practices of handling war graves by presenting historical and recent examples., Competing Interests: Declaration of Competing Interest We have no conflicting interests to declare., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
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321. Meeting report on the NIDDK/AUA Workshop on Congenital Anomalies of External Genitalia: challenges and opportunities for translational research.
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Stadler HS, Peters CA, Sturm RM, Baker LA, Best CJM, Bird VY, Geller F, Hoshizaki DK, Knudsen TB, Norton JM, Romao RLP, and Cohn MJ
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- Adult, Animals, Genitalia, Humans, Male, National Institute of Diabetes and Digestive and Kidney Diseases (U.S.), Translational Research, Biomedical, United States, Bladder Exstrophy, Epispadias
- Abstract
Congenital anomalies of the external genitalia (CAEG) are a prevalent and serious public health concern with lifelong impacts on the urinary function, sexual health, fertility, tumor development, and psychosocial wellbeing of affected individuals. Complications of treatment are frequent, and data reflecting long-term outcomes in adulthood are limited. To identify a path forward to improve treatments and realize the possibility of preventing CAEG, the National Institute of Diabetes and Digestive and Kidney Diseases and the American Urological Association convened researchers from a range of disciplines to coordinate research efforts to fully understand the different etiologies of these common conditions, subsequent variation in clinical phenotypes, and best practices for long term surgical success. Meeting participants concluded that a central data hub for clinical evaluations, including collection of DNA samples from patients and their parents, and short interviews to determine familial penetrance (small pedigrees), would accelerate research in this field. Such a centralized datahub will advance efforts to develop detailed multi-dimensional phenotyping and will enable access to genome sequence analyses and associated metadata to define the genetic bases for these conditions. Inclusion of tissue samples and integration of clinical studies with basic research using human cells and animal models will advance efforts to identify the developmental mechanisms that are disrupted during development and will add cellular and molecular granularity to phenotyping CAEG. While the discussion focuses heavily on hypospadias, this can be seen as a potential template for other conditions in the realm of CAEG, including cryptorchidism or the exstrophy-epispadias complex. Taken together with long-term clinical follow-up, these data could inform surgical choices and improve likelihood for long-term success., Competing Interests: Conflicts of interest The authors declare no conflicts of interest., (Copyright © 2020 Journal of Pediatric Urology Company. All rights reserved.)
- Published
- 2020
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322. Efficient and reproducible depletion of hepatitis B virus from plasma derived extracellular vesicles.
- Author
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Jung S, Jacobs KFK, Shein M, Schütz AK, Mohr F, Stadler H, Stadler D, Lucko AM, Altstetter SM, Wilsch F, Deng L, and Protzer U
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- Extracellular Vesicles chemistry, Extracellular Vesicles virology, Hepatitis B pathology, Hepatitis B virology, Humans, Plasma virology, Chromatography, Affinity methods, Chromatography, Gel methods, Extracellular Vesicles physiology, Hepatitis B metabolism, Hepatitis B virus physiology, Plasma metabolism
- Abstract
Extracellular vesicles (EVs) are emerging fundamental players in viral infections by shuttling viral components, mediating immune responses and likely the spread of the virus. However, the obstacles involved in purifying EVs and removing contaminating viral particles in a reliable and effective manner bottlenecks the full potential for the development of clinical and diagnostic treatment options targeting EV. Because of the similarities in size, density, membrane composition and mode of biogenesis of EVs and virions there are no standardized approaches for virus-removal from EV preparations yet. Functional EV studies also require EV samples that are devoid of antibody contaminants. Consequently, the study of EVs in virology needs reliable and effective protocols to purify EVs and remove contaminating antibodies and viral particles. Here, we established a protocol for EV purification from hepatitis B virus (HBV)-containing plasma by a combination of size-exclusion chromatography and affinity-based purification. After purification, EV samples were free of virus-sized particles, HBV surface antigen, HBV core antigen, antibodies or infectious material. Viral genomic contamination was also decreased following purification. By using appropriate antibodies and size parameters, this protocol could potentially be applied to purification of EVs from other viral samples. In summary, we established a fast, reproducible and robust approach for the removal of HBV from EV preparations. Looking forward to the point of purifying EVs from clinical samples, this method should enable studies shedding light on the underlying mechanisms of EVs in viral infections and their diagnostic and prognostic potential., Competing Interests: The position of Daniela Stadler was in part financed by a research grant from ALIOS BioPharma., (© 2020 The Authors. Journal of Extracellular Vesicles published by Wiley Periodicals LLC on behalf of International Society for Extracellular Vesicles.)
- Published
- 2020
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323. Encouraging cartilage production.
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Stadler HS
- Subjects
- Chondrogenesis, Interferon-gamma, Signal Transduction, Tissue Engineering, Cartilage, Articular, Mesenchymal Stem Cell Transplantation, Mesenchymal Stem Cells, RNA, Long Noncoding
- Abstract
A long non-coding RNA called GRASLND is essential to help stem cells create stable cartilage., Competing Interests: HS No competing interests declared, (© 2020, Stadler.)
- Published
- 2020
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324. Development and functional characterization of a lncRNA-HIT conditional loss of function allele.
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Carlson HL and Stadler HS
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- Animals, Computational Biology methods, Embryonic Development genetics, Gene Expression Regulation, Developmental, Gene Targeting, Humans, Mice, Organ Specificity, Phenotype, RNA, Small Interfering genetics, Transcriptional Activation, Alleles, Gene Expression Profiling, Gene Silencing, RNA, Long Noncoding genetics, Transcriptome
- Abstract
Analysis of the human and murine transcriptomes has identified long noncoding RNAs (lncRNAs) as major functional components in both species. Transcriptional profiling of the murine limb led to our discovery of lncRNA-HIT, which our previous in vitro analyses suggested a potential role for this lncRNA in the development of limb, craniofacial, and genitourinary tissues (Carlson et al., 2015). To test this hypothesis, we developed a conditional lncRNA-HIT loss of function allele which uses Cre recombinase to activate an shRNA specific for lncRNA-HIT. Activation of the lncRNA-HIT shRNA allele resulted in a robust knock-down of lncRNA-HIT as well as co-activation of a mCherry reporter, confirming the efficacy of the shRNA allele to reduce endogenous lncRNA levels in a tissue- and cell-type specific manner. Developmental analyses of embryos expressing the activated shRNA and mCherry co-reporter revealed multiple malformations corresponding to the sites of shRNA activation, affecting craniofacial, limb, and genitourinary tissue development. These results confirm the efficacy of lncRNA-HIT shRNA allele to knock-down endogenous transcripts in tissue- and cell type specific manner and indicate a requirement for lncRNA-HIT in the development of these tissues., (© 2019 Wiley Periodicals, Inc.)
- Published
- 2020
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325. An Evaluation of T-Cell Functionality After Flow Cytometry Sorting Revealed p38 MAPK Activation.
- Author
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Andrä I, Ulrich H, Dürr S, Soll D, Henkel L, Angerpointner C, Ritter J, Przibilla S, Stadler H, Effenberger M, Busch DH, and Schiemann M
- Subjects
- Cell Separation, Flow Cytometry, Humans, Signal Transduction, T-Lymphocytes metabolism, p38 Mitogen-Activated Protein Kinases metabolism
- Abstract
Cell alterations during isolation and preparation for flow cytometry cell sorting by antibodies, temperature, homogenization, buffer composition and mitogens are well known. In contrast, little is known about cell alteration caused by the instrument or the sorting process itself. We systematically evaluated cellular responses to different sorter-induced physical forces. In summary, flow cytometry cell-sorting induced forces can affect cellular signaling cascades, especially the MAPK p38. Functional assays, related to the p38 MAPK pathway, of human primary T cells after flow cytometry sorting did lead to minor physiological modulation but no functional impairments. © 2020 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry., (© 2020 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.)
- Published
- 2020
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326. Disrupting the endocannabinoid system in early adolescence negatively impacts sociability.
- Author
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Cossio D, Stadler H, Michas Z, Johnston C, and Lopez HH
- Subjects
- Age Factors, Analgesics pharmacology, Animals, Conditioning, Operant drug effects, Conditioning, Operant physiology, Cyclohexanols pharmacology, Endocannabinoids metabolism, Female, Male, Maze Learning drug effects, Maze Learning physiology, Piperidines pharmacology, Pyrazoles pharmacology, Rats, Rats, Long-Evans, Receptor, Cannabinoid, CB1 metabolism, Endocannabinoids agonists, Endocannabinoids antagonists & inhibitors, Receptor, Cannabinoid, CB1 agonists, Receptor, Cannabinoid, CB1 antagonists & inhibitors, Social Interaction drug effects
- Abstract
Animal models suggest that the endocannabinoid system (eCS) helps regulate various aspects of social behavior, including play behavior and social reward, during adolescence. Properly tuned endocannabinoid signaling may be a critical developmental component in the emergence of normal adult sociability. In the current experiment, we attempted to pharmacologically disrupt endocannabinoid tone during early adolescence, and then measure the behavioral effects at two subsequent time points. 36 male and 36 female Long Evans rats received daily injections of one of three treatments between post-natal day (PND) 25-39: 1) vehicle treatment, 2) 0.4 mg/kg CP55,940 (a potent CB1/CB2 receptor agonist), or 3) 0.5 mg/kg AM251 (a CB1 receptor antagonist/inverse agonist). Both soon after treatment (PND 40-44) and several weeks later (PND 66-70), subjects were tested in an elevated plus maze (EPM) for anxiety and in a three-chambered apparatus for sociability. For the latter test, the number of entries into each chamber and the amount of time spent investigating each target were measured. Analyses revealed significant main effects of both sex and age on sociability: males expressed greater sociability compared to females, and sociability was higher in adolescence than adulthood. Most importantly, drug treatment (both CP55,940 and AM251) attenuated sociability in adolescence without having a significant effect on anxiety in the EPM. However, this effect did not persist into adulthood. These results indicate that pharmacological disruption of endocannabinoid tone - through either chronic agonism or antagonism of cannabinoid receptors - during early adolescence has a detrimental effect on sociability. This effect may be caused by transient, compensatory alterations in the eCS., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2020
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327. Spring Water of an Alpine Karst Aquifer Is Dominated by a Taxonomically Stable but Discharge-Responsive Bacterial Community.
- Author
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Savio D, Stadler P, Reischer GH, Demeter K, Linke RB, Blaschke AP, Mach RL, Kirschner AKT, Stadler H, and Farnleitner AH
- Abstract
Alpine karst aquifers are important groundwater resources for the provision of drinking water all around the world. Yet, due to difficult accessibility and long-standing methodological limitations, the microbiology of these systems has long been understudied. The aim of the present study was to investigate the structure and dynamics of bacterial communities in spring water of an alpine limestone karst aquifer (LKAS2) under different hydrological conditions (base vs. event flow). The study was based on high-throughput 16S rRNA gene amplicon sequencing, study design and sample selection were guided by hydrology and pollution microbiology data. Spanning more than 27 months, our analyses revealed a taxonomically highly stable bacterial community, comprising high proportions of yet uncultivated bacteria in the suspended bacterial community fraction. Only the three candidate phyla Parcubacteria (OD1), Gracilibacteria (GN02), Doudnabacteria (SM2F11) together with Proteobacteria and Bacteroidetes contributed between 70.0 and 88.4% of total reads throughout the investigation period. A core-community of 300 OTUs consistently contributed between 37.6 and 56.3% of total reads, further supporting the hypothesis of a high temporal stability in the bacterial community in the spring water. Nonetheless, a detectable response in the bacterial community structure of the spring water was discernible during a high-discharge event. Sequence reads affiliated to the class Flavobacteriia clearly increased from a mean proportion of 2.3% during baseflow to a maximum of 12.7% during the early phase of the studied high-discharge event, suggesting direct impacts from changing hydrological conditions on the bacterial community structure in the spring water. This was further supported by an increase in species richness (Chao1) at higher discharge. The combination of these observations allowed the identification and characterization of three different discharge classes (Q1-Q3). In conclusion, we found a taxonomically stable bacterial community prevailing in spring waters from an alpine karst aquifer over the entire study period of more than 2 years. Clear response to changing discharge conditions could be detected for particular bacterial groups, whereas the most responsive group - bacteria affiliated to the class of Flavobacteriia - might harbor potential as a valuable natural indicator of "system disturbances" in karst aquifers.
- Published
- 2019
- Full Text
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328. Efficient immunoaffinity chromatography of lymphocytes directly from whole blood.
- Author
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Mohr F, Przibilla S, Leonhardt F, Stemberger C, Dreher S, Müller TR, Fräßle SP, Schmidt GP, Kiene ML, Stadler H, and Busch DH
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Female, Humans, Male, Middle Aged, Young Adult, Chromatography, Affinity methods, Lymphocytes cytology
- Abstract
We show that defined lymphocytes can be rapidly purified by immunoaffinity chromatography starting directly from whole blood. The method relies on low-affinity Fab-fragments attached to a column-matrix combined with the reversible Strep-tag technology. Compared to established cell enrichment protocols, the Strep-tag affinity chromatography of cells is independent of erythrocyte lysis or centrifugation steps, allowing for simple cell-enrichment with good yields, high purities, and excellent functionality of purified cells.
- Published
- 2018
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329. Opening the black box of spring water microbiology from alpine karst aquifers to support proactive drinking water resource management.
- Author
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Savio D, Stadler P, Reischer GH, Kirschner AKT, Demeter K, Linke R, Blaschke AP, Sommer R, Szewzyk U, Wilhartitz IC, Mach RL, Stadler H, and Farnleitner AH
- Abstract
Over the past 15 years, pioneering interdisciplinary research has been performed on the microbiology of hydrogeologically well-defined alpine karst springs located in the Northern Calcareous Alps (NCA) of Austria. This article gives an overview on these activities and links them to other relevant research. Results from the NCA springs and comparable sites revealed that spring water harbors abundant natural microbial communities even in aquifers with high water residence times and the absence of immediate surface influence. Apparently, hydrogeology has a strong impact on the concentration and size of the observed microbes, and total cell counts (TCC) were suggested as a useful means for spring type classification. Measurement of microbial activities at the NCA springs revealed extremely low microbial growth rates in the base flow component of the studied spring waters and indicated the importance of biofilm-associated microbial activities in sediments and on rock surfaces. Based on genetic analysis, the autochthonous microbial endokarst community (AMEC) versus transient microbial endokarst community (TMEC) concept was proposed for the NCA springs, and further details within this overview article are given to prompt its future evaluation. In this regard, it is well known that during high-discharge situations, surface-associated microbes and nutrients such as from soil habitats or human settlements-potentially containing fecal-associated pathogens as the most critical water-quality hazard-may be rapidly flushed into vulnerable karst aquifers. In this context, a framework for the comprehensive analysis of microbial pollution has been proposed for the NCA springs to support the sustainable management of drinking water safety in accordance with recent World Health Organization guidelines. Near-real-time online water quality monitoring, microbial source tracking (MST) and MST-guided quantitative microbial-risk assessment (QMRA) are examples of the proposed analytical tools. In this context, this overview article also provides a short introduction to recently emerging methodologies in microbiological diagnostics to support reading for the practitioner. Finally, the article highlights future research and development needs. This article is categorized under: 1Engineering Water > Water, Health, and Sanitation2Science of Water > Water Extremes3Water and Life > Nature of Freshwater Ecosystems.
- Published
- 2018
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330. EV-3, an endogenous human erythropoietin isoform with distinct functional relevance.
- Author
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Bonnas C, Wüstefeld L, Winkler D, Kronstein-Wiedemann R, Dere E, Specht K, Boxberg M, Tonn T, Ehrenreich H, Stadler H, and Sillaber I
- Subjects
- Amino Acid Sequence, Cell Line, Tumor, Colony-Forming Units Assay, Erythropoietin chemistry, Erythropoietin pharmacology, Gene Expression Regulation, Hematopoietic Stem Cells cytology, Hematopoietic Stem Cells drug effects, Hematopoietic Stem Cells metabolism, Humans, Hypoxia metabolism, Immunoprecipitation, Male, Models, Molecular, Protein Conformation, Protein Isoforms, Pyramidal Cells cytology, Pyramidal Cells metabolism, Recombinant Proteins, Structure-Activity Relationship, Erythropoietin genetics, Erythropoietin metabolism, RNA Splicing genetics
- Abstract
Generation of multiple mRNAs by alternative splicing is well known in the group of cytokines and has recently been reported for the human erythropoietin (EPO) gene. Here, we focus on the alternatively spliced EPO transcript characterized by deletion of exon 3 (hEPOΔ3). We show co-regulation of EPO and hEPOΔ3 in human diseased tissue. The expression of hEPOΔ3 in various human samples was low under normal conditions, and distinctly increased in pathological states. Concomitant up-regulation of hEPOΔ3 and EPO in response to hypoxic conditions was also observed in HepG2 cell cultures. Using LC-ESI-MS/MS, we provide first evidence for the existence of hEPOΔ3 derived protein EV-3 in human serum from healthy donors. Contrary to EPO, recombinant EV-3 did not promote early erythroid progenitors in cultures of human CD34+ haematopoietic stem cells. Repeated intraperitoneal administration of EV-3 in mice did not affect the haematocrit. Similar to EPO, EV-3 acted anti-apoptotic in rat hippocampal neurons exposed to oxygen-glucose deprivation. Employing the touch-screen paradigm of long-term visual discrimination learning, we obtained first in vivo evidence of beneficial effects of EV-3 on cognition. This is the first report on the presence of a naturally occurring EPO protein isoform in human serum sharing non-erythropoietic functions with EPO.
- Published
- 2017
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331. Lymphocyte enrichment using CD81-targeted immunoaffinity matrix.
- Author
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Pelák O, Kužílková D, Thürner D, Kiene ML, Stanar K, Stuchlý J, Vášková M, Starý J, Hrušák O, Stadler H, and Kalina T
- Subjects
- Antibodies chemistry, Antibodies immunology, Cell Survival immunology, Ficoll chemistry, Humans, Lymphocytes immunology, Tetraspanin 28 chemistry, Tetraspanin 28 metabolism, Cell Separation methods, Image Cytometry methods, Leukocytes, Mononuclear cytology, Lymphocytes cytology
- Abstract
In mass cytometry, the isolation of pure lymphocytes is very important to obtain reproducible results and to shorten the time spent on data acquisition. To prepare highly purified cell suspensions of peripheral blood lymphocytes for further analysis on mass cytometer, we used the new CD81+ immune affinity chromatography cell isolation approach. Using 21 metal conjugated antibodies in a single tube we were able to identify all basic cell subsets and compare their relative abundance in final products obtained by density gradient (Ficoll-Paque) and immune affinity chromatography (CD81+ T-catch™) isolation approach. We show that T-catch isolation approach results in purer final product than Ficoll-Paque (P values 0.0156), with fewer platelets bound to target cells. As a result acquisition time of 10
5 nucleated cells was 3.5 shorter. We then applied unsupervised high dimensional analysis viSNE algorithm to compare the two isolation protocols, which allowed us to evaluate the contribution of unsupervised analysis over supervised manual gating. ViSNE algorithm effectively characterized almost all supervised cell subsets. Moreover, viSNE uncovered previously overseen cell subsets and showed inaccuracies in Maxpar™ Human peripheral blood phenotyping panel kit recommended gating strategy. These findings emphasize the use of unsupervised analysis tools in parallel with conventional gating strategy to mine the complete information from a set of samples. They also stress the importance of the impurity removal to sensitively detect rare cell populations in unsupervised analysis. © 2016 International Society for Advancement of Cytometry., (© 2016 International Society for Advancement of Cytometry.)- Published
- 2017
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332. Distal Limb Patterning Requires Modulation of cis-Regulatory Activities by HOX13.
- Author
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Sheth R, Barozzi I, Langlais D, Osterwalder M, Nemec S, Carlson HL, Stadler HS, Visel A, Drouin J, and Kmita M
- Subjects
- Animals, Chromatin genetics, Gene Expression Regulation, Developmental, Homeodomain Proteins metabolism, Mice, Mice, Knockout, Protein Binding, Transcription Factors metabolism, Body Patterning genetics, Extremities growth & development, Homeodomain Proteins genetics, Transcription Factors genetics
- Abstract
The combinatorial expression of Hox genes along the body axes is a major determinant of cell fate and plays a pivotal role in generating the animal body plan. Loss of HOXA13 and HOXD13 transcription factors (HOX13) leads to digit agenesis in mice, but how HOX13 proteins regulate transcriptional outcomes and confer identity to the distal-most limb cells has remained elusive. Here, we report on the genome-wide profiling of HOXA13 and HOXD13 in vivo binding and changes of the transcriptome and chromatin state in the transition from the early to the late-distal limb developmental program, as well as in Hoxa13
-/- ; Hoxd13-/- limbs. Our results show that proper termination of the early limb transcriptional program and activation of the late-distal limb program are coordinated by the dual action of HOX13 on cis-regulatory modules., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2016
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333. Evolution of Hoxa11 regulation in vertebrates is linked to the pentadactyl state.
- Author
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Kherdjemil Y, Lalonde RL, Sheth R, Dumouchel A, de Martino G, Pineault KM, Wellik DM, Stadler HS, Akimenko MA, and Kmita M
- Subjects
- Animal Fins anatomy & histology, Animal Fins metabolism, Animals, Enhancer Elements, Genetic genetics, Extinction, Biological, Female, Introns genetics, Mice, RNA, Antisense biosynthesis, RNA, Antisense genetics, Transcription Factors metabolism, Transcription, Genetic, Zebrafish anatomy & histology, Zebrafish genetics, Biological Evolution, Extremities anatomy & histology, Homeodomain Proteins metabolism, Vertebrates anatomy & histology, Vertebrates genetics
- Abstract
The fin-to-limb transition represents one of the major vertebrate morphological innovations associated with the transition from aquatic to terrestrial life and is an attractive model for gaining insights into the mechanisms of morphological diversity between species. One of the characteristic features of limbs is the presence of digits at their extremities. Although most tetrapods have limbs with five digits (pentadactyl limbs), palaeontological data indicate that digits emerged in lobed fins of early tetrapods, which were polydactylous. How the transition to pentadactyl limbs occurred remains unclear. Here we show that the mutually exclusive expression of the mouse genes Hoxa11 and Hoxa13, which were previously proposed to be involved in the origin of the tetrapod limb, is required for the pentadactyl state. We further demonstrate that the exclusion of Hoxa11 from the Hoxa13 domain relies on an enhancer that drives antisense transcription at the Hoxa11 locus after activation by HOXA13 and HOXD13. Finally, we show that the enhancer that drives antisense transcription of the mouse Hoxa11 gene is absent in zebrafish, which, together with the largely overlapping expression of hoxa11 and hoxa13 genes reported in fish, suggests that this enhancer emerged in the course of the fin-to-limb transition. On the basis of the polydactyly that we observed after expression of Hoxa11 in distal limbs, we propose that the evolution of Hoxa11 regulation contributed to the transition from polydactyl limbs in stem-group tetrapods to pentadactyl limbs in extant tetrapods.
- Published
- 2016
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334. Co-Expression of Wild-Type P2X7R with Gln460Arg Variant Alters Receptor Function.
- Author
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Aprile-Garcia F, Metzger MW, Paez-Pereda M, Stadler H, Acuña M, Liberman AC, Senin SA, Gerez J, Hoijman E, Refojo D, Mitkovski M, Panhuysen M, Stühmer W, Holsboer F, Deussing JM, and Arzt E
- Subjects
- Blotting, Western, Calcium metabolism, Calcium physiology, Fluorescence Resonance Energy Transfer, HEK293 Cells, Humans, Immunoprecipitation, Patch-Clamp Techniques, Polymorphism, Single Nucleotide physiology, RNA, Small Interfering metabolism, Real-Time Polymerase Chain Reaction, Receptors, Purinergic P2X7 genetics, Receptors, Purinergic P2X7 metabolism, Signal Transduction physiology, Polymorphism, Single Nucleotide genetics, Receptors, Purinergic P2X7 physiology
- Abstract
The P2X7 receptor is a member of the P2X family of ligand-gated ion channels. A single-nucleotide polymorphism leading to a glutamine (Gln) by arginine (Arg) substitution at codon 460 of the purinergic P2X7 receptor (P2X7R) has been associated with mood disorders. No change in function (loss or gain) has been described for this SNP so far. Here we show that although the P2X7R-Gln460Arg variant per se is not compromised in its function, co-expression of wild-type P2X7R with P2X7R-Gln460Arg impairs receptor function with respect to calcium influx, channel currents and intracellular signaling in vitro. Moreover, co-immunoprecipitation and FRET studies show that the P2X7R-Gln460Arg variant physically interacts with P2X7R-WT. Specific silencing of either the normal or polymorphic variant rescues the heterozygous loss of function phenotype and restores normal function. The described loss of function due to co-expression, unique for mutations in the P2RX7 gene so far, explains the mechanism by which the P2X7R-Gln460Arg variant affects the normal function of the channel and may represent a mechanism of action for other mutations.
- Published
- 2016
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335. Widespread Expression of Erythropoietin Receptor in Brain and Its Induction by Injury.
- Author
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Ott C, Martens H, Hassouna I, Oliveira B, Erck C, Zafeiriou MP, Peteri UK, Hesse D, Gerhart S, Altas B, Kolbow T, Stadler H, Kawabe H, Zimmermann WH, Nave KA, Schulz-Schaeffer W, Jahn O, and Ehrenreich H
- Abstract
Erythropoietin (EPO) exerts potent neuroprotective, neuroregenerative and procognitive functions. However, unequivocal demonstration of erythropoietin receptor (EPOR) expression in brain cells has remained difficult since previously available anti-EPOR antibodies (EPOR-AB) were unspecific. We report here a new, highly specific, polyclonal rabbit EPOR-AB directed against different epitopes in the cytoplasmic tail of human and murine EPOR and its characterization by mass spectrometric analysis of immuno-precipitated endogenous EPOR, Western blotting, immunostaining and flow cytometry. Among others, we applied genetic strategies including overexpression, Lentivirus-mediated conditional knockout of EpoR and tagged proteins, both on cultured cells and tissue sections, as well as intracortical implantation of EPOR -transduced cells to verify specificity. We show examples of EPOR expression in neurons, oligodendroglia, astrocytes and microglia. Employing this new EPOR-AB with double-labeling strategies, we demonstrate membrane expression of EPOR as well as its localization in intracellular compartments such as the Golgi apparatus. Moreover, we show injury-induced expression of EPOR. In mice, a stereotactically applied stab wound to the motor cortex leads to distinct EpoR expression by reactive GFAP-expressing cells in the lesion vicinity. In a patient suffering from epilepsy, neurons and oligodendrocytes of the hippocampus strongly express EPOR. To conclude, this new analytical tool will allow neuroscientists to pinpoint EPOR expression in cells of the nervous system and to better understand its role in healthy conditions, including brain development, as well as under pathological circumstances, such as upregulation upon distress and injury.
- Published
- 2015
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336. Chemical shift assignments of mouse HOXD13 DNA binding domain bound to duplex DNA.
- Author
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Turner M, Zhang Y, Carlson HL, Stadler HS, and Ames JB
- Subjects
- Amino Acid Sequence, Animals, Mice, Molecular Sequence Data, Protein Structure, Secondary, Protein Structure, Tertiary, Proton Magnetic Resonance Spectroscopy, DNA metabolism, Homeodomain Proteins chemistry, Homeodomain Proteins metabolism, Nuclear Magnetic Resonance, Biomolecular, Transcription Factors chemistry, Transcription Factors metabolism
- Abstract
The homeobox gene (Hoxd13) codes for a transcription factor protein that binds to AT-rich DNA sequences and controls expression of proteins that control embryonic morphogenesis. We report NMR chemical shift assignments of mouse Hoxd13 DNA binding domain bound to an 11-residue DNA duplex (BMRB No. 25133).
- Published
- 2015
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337. Comparison of morphological and molecular genetic sex-typing on mediaeval human skeletal remains.
- Author
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Bauer CM, Niederstätter H, McGlynn G, Stadler H, and Parson W
- Subjects
- Archaeology, Base Sequence, DNA genetics, DNA Primers, Female, Humans, Male, Multiplex Polymerase Chain Reaction, Real-Time Polymerase Chain Reaction, Fossils, Sex Determination by Skeleton
- Abstract
Archaeological excavations conducted at an early mediaeval cemetery in Volders (Tyrol, Austria) produced 141 complete skeletal remains dated between the 5th/6th and 12th/13th centuries. These skeletons represent one of the largest historical series of human remains ever discovered in the East Alpine region. Little historical information is available for this region and time period. The good state of preservation of these bioarchaeological finds offered the opportunity of performing molecular genetic investigations. Adequate DNA extraction methods were tested in the attempt to obtain as high DNA yields as possible for further analyses. Molecular genetic sex-typing using a dedicated PCR multiplex ("Genderplex") gave interpretable results in 88 remains, 78 of which had previously been sexed based on morphological features. We observed a discrepancy in sex determination between the two methods in 21 cases. An unbiased follow-up morphological examination of these finds showed congruence with the DNA results in all but five samples., (Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.)
- Published
- 2013
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338. Dynamics of natural prokaryotes, viruses, and heterotrophic nanoflagellates in alpine karstic groundwater.
- Author
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Wilhartitz IC, Kirschner AK, Brussaard CP, Fischer UR, Wieltschnig C, Stadler H, and Farnleitner AH
- Subjects
- Groundwater parasitology, Seasons, Bacterial Load, Biota, Groundwater microbiology, Groundwater virology, Parasite Load, Viral Load
- Abstract
Seasonal dynamics of naturally occurring prokaryotes, viruses, and heterotrophic nanoflagellates in two hydro-geologically contrasting alpine karst springs were monitored over three annual cycles. To our knowledge, this study is the first to shed light on the occurrence and possible interrelationships between these three groups in karstic groundwater. Hydrological and microbiological standard indicators were recovered simultaneously in order to estimate surface influence, especially during rainfall events. Data revealed a strong dependence of the microbial communities on the prevailing hydrological situation. Prokaryotic numbers averaged 5.1 × 10(7) and 1.3 × 10(7) cells L(-1) , and heterotrophic nanoflagellate abundance averaged 1.1 × 10(4) and 3 × 10(3) cells L(-1) in the limestone spring type (LKAS2) and the dolomitic spring type (DKAS1), respectively. Viral abundance in LKAS2 and DKAS1 averaged 9.4 × 10(8) and 1.1 × 10(8) viruses L(-1) . Unlike in DKAS1, the dynamic spring type LKAS2 revealed a clear difference between base flow and high discharge conditions. The virus-to-prokaryotes ratio was generally lower by a factor of 2-3, at higher average water residence times. Furthermore, the high prokaryotes-to-heterotrophic nanoflagellate ratios, namely about 4700 and 5400 for LKAS2 and DKAS1, respectively, pointed toward an uncoupling of these two groups in the planktonic fraction of alpine karstic aquifers., (© 2013 The Authors. Microbiology Open published by John Wiley & Sons Ltd.)
- Published
- 2013
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339. Analysis of de novo HOXA13 polyalanine expansions supports replication slippage without repair in their generation.
- Author
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Owens KM, Quinonez SC, Thomas PE, Keegan CE, Lefebvre N, Roulston D, Larsen CA, Stadler HS, and Innis JW
- Subjects
- Adolescent, Adult, Female, Humans, Infant, Newborn, Male, Mutation, Peptides, Phenotype, Abnormalities, Multiple genetics, DNA Repeat Expansion genetics, Foot Deformities, Congenital genetics, Hand Deformities, Congenital genetics, Homeodomain Proteins genetics, Urogenital Abnormalities genetics
- Abstract
Polyalanine repeat expansion diseases are hypothesized to result from unequal chromosomal recombination, yet mechanistic studies are lacking. We identified two de novo cases of hand-foot-genital syndrome (HFGS) associated with polyalanine expansions in HOXA13 that afforded rare opportunities to investigate the mechanism. The first patient with HFGS was heterozygous for a de novo nine codon polyalanine expansion. Haplotype investigation showed that the expansion arose on the maternally inherited chromosome but not through unequal crossing over between homologs, leaving unequal sister chromatid exchange during mitosis or meiosis or slipped mispairing as possible explanations. The asymptomatic father of the second patient with HFGS was mosaic for a six codon polyalanine expansion. Multiple tissue PCR and clonal analysis of paternal fibroblasts showed only expansion/WT and WT/WT clones, and haplotype data showed that two unaffected offspring inherited the same paternal allele without the expansion, supporting a postzygotic origin. Absence of the contracted allele in the mosaic father does not support sister chromatid exchange in the origin of the expansion. Mosaicism for HOXA13 polyalanine expansions may be associated with a normal phenotype, making examination of parental DNA essential in apparently de novo HFGS cases to predict accurate recurrence risks. We could not find an example in the literature where unequal sister chromatid exchange has been proven for any polyalanine expansion, suggesting that the principal mechanism for polyalanine expansions (and contractions) is slipped mispairing without repair or that the true frequency of unequal sister chromatid exchange involving these repeats is low., (Copyright © 2013 Wiley Periodicals, Inc.)
- Published
- 2013
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340. Solvent-free preparation of high-toughness epoxy--SWNT composite materials.
- Author
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González-Domínguez JM, Ansón-Casaos A, Díez-Pascual AM, Ashrafi B, Naffakh M, Backman D, Stadler H, Johnston A, Gómez M, and Martínez MT
- Abstract
Multicomponent nanocomposite materials based on a high-performance epoxy system and single-walled carbon nanotubes (SWNTs) have been prepared. The noncovalent wrapping of nitric acid-treated SWNTs with a PEO-based amphiphilic block copolymer leads to a highly disaggregated filler with a boosted miscibility in the epoxy matrix, allowing its dispersion without organic solvents. Although direct dispersion of acid-treated SWNTs results in modestly improved epoxy matrix mechanical properties, the incorporation of wrapped SWNTs produces a huge increase in toughness (276% improvement at 0.5 wt % loading) and impact strength (193% at 0.5 wt % loading) with no detrimental effect on the elastic properties. A synergistic effect between SWNTs and the block copolymer is revealed on the basis of tensile and impact strength results. Atomic force microscopy has been applied, obtaining stiffness mappings that identify nanostructure features responsible of the dynamic mechanical behavior. The electrical percolation threshold is greatly reduced, from 0.31 to 0.03 wt % SWNTs when block copolymer-wrapped SWNTs are used, and all the measured conductivity values increased up to a maximum of 7 orders of magnitude with respect to the baseline matrix (1 wt % wrapped-SWNTs loading). This approach provides an efficient way to disperse barely dispersible SWNTs without solvents into an epoxy matrix, and to generate substantial improvements with small amounts of SWNTs.
- Published
- 2011
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341. Altered distribution of mGlu2 receptors in β-amyloid-affected brain regions of Alzheimer cases and aged PS2APP mice.
- Author
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Richards G, Messer J, Faull RL, Stadler H, Wichmann J, Huguenin P, Bohrmann B, and Mutel V
- Subjects
- Aged, Aged, 80 and over, Aging pathology, Alzheimer Disease pathology, Amyloid beta-Peptides pharmacology, Animals, Bridged Bicyclo Compounds metabolism, Bridged Bicyclo Compounds pharmacology, Excitatory Amino Acid Agonists metabolism, Excitatory Amino Acid Agonists pharmacology, Hippocampus pathology, Humans, Iodine Radioisotopes, Male, Mice, Mice, Inbred C57BL, Mice, Inbred DBA, Mice, Transgenic, Peptide Fragments pharmacology, Presenilin-2 genetics, Radioligand Assay, Rats, Rats, Inbred F344, Tritium, Aging metabolism, Alzheimer Disease metabolism, Amyloid beta-Peptides metabolism, Hippocampus metabolism, Peptide Fragments metabolism, Presenilin-2 metabolism, Receptors, Metabotropic Glutamate metabolism
- Abstract
Altered glutamatergic synaptic transmission is among the key events defining the course of Alzheimer's disease (AD). mGlu2 receptors, a subtype of group II metabotropic glutamate receptors, regulate (as autoreceptors) fast synaptic transmission in the CNS via the controlled release of the excitatory amino acid glutamate. Since their pharmacological manipulation in rodents has been reported to affect cognition, they are potential drug targets for AD therapy. We examined the fate of these receptors in cases of AD as well as in aging PS2APP mice--a proposed model of the disease. In vitro binding of [(3)H]LY354740, a selective group II agonist (with selective affinity for mGlu2 receptors, under the assay conditions used) and quantitative radioautography revealed a partial, but highly significant, loss of receptors in amyloid-affected discrete brain regions of AD cases and PS2APP mice. Among the mouse brain regions affected were, above all, the subiculum but also frontolateral cortex, dentate gyrus, lacunosum moleculare and caudate putamen. In AD, significant receptor losses were registered in entorhinal cortex and lacunosum moleculare (40% and 35%, respectively). These findings have implications for the development of selective ligands for symptomatic therapy in AD and for its diagnosis., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
342. Discovery of potent, balanced and orally active dual NK1/NK3 receptor ligands.
- Author
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Peters JU, Hoffmann T, Schnider P, Stadler H, Koblet A, Alker A, Poli SM, Ballard TM, Spooren W, Steward L, and Sleight AJ
- Subjects
- Administration, Oral, Animals, Drug Discovery, Ligands, Models, Molecular, Receptors, Neurokinin-1 metabolism, Receptors, Neurokinin-3 metabolism, Neurokinin-1 Receptor Antagonists, Receptors, Neurokinin-3 antagonists & inhibitors
- Abstract
During a program directed at selective NK(1) receptor antagonists, we serendipitously discovered an NK(1) receptor ligand with additional affinity for the NK(3) receptor. Recognising an opportunity for a drug discovery program aiming for dual NK(1)/NK(3) receptor antagonists, we prepared a series of analogues from a novel, versatile building block. From this series emerged compounds with high and balanced affinities for the NK(1) and the NK(3) receptors. Typical representatives of this series were active in the gerbil foot tapping assay after oral administration., (Copyright 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
343. Backbone chemical shift assignments of mouse HOXA13 DNA binding domain bound to duplex DNA.
- Author
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Zhang Y, Thornburg CK, Stadler HS, and Ames JB
- Subjects
- Amino Acid Sequence, Animals, DNA metabolism, Homeodomain Proteins genetics, Homeodomain Proteins metabolism, Mice, Molecular Sequence Data, Nuclear Magnetic Resonance, Biomolecular, Protein Structure, Secondary, Protein Structure, Tertiary, DNA chemistry, Homeodomain Proteins chemistry
- Abstract
The homeobox gene (Hoxa13) codes for a transcription factor protein that binds to AT-rich DNA sequences and controls expression of many important proteins during embryonic morphogenesis. We report complete backbone NMR chemical shift assignments of mouse Hoxa13 DNA binding domain bound to an 11-residue DNA duplex (BMRB no. 16577).
- Published
- 2010
- Full Text
- View/download PDF
344. (1)H, (15)N, and (13)C chemical shift assignments of mouse HOXA13 DNA binding domain.
- Author
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Zhang Y, Thornburg CK, Stadler HS, and Ames JB
- Subjects
- Animals, Hydrogen-Ion Concentration, Mice, Nuclear Magnetic Resonance, Biomolecular, Protein Structure, Tertiary, Substrate Specificity, DNA metabolism, Homeodomain Proteins chemistry, Homeodomain Proteins metabolism
- Abstract
The homeobox gene (HOXA13) codes for a transcription factor protein that binds to AT-rich DNA sequences and controls expression of many important proteins during embryonic morphogenesis. We report complete NMR chemical shift assignments of the mouse HOXA13 DNA binding domain (A13DBD; BMRB no. 16252).
- Published
- 2009
- Full Text
- View/download PDF
345. The discovery and unique pharmacological profile of RO4938581 and RO4882224 as potent and selective GABAA alpha5 inverse agonists for the treatment of cognitive dysfunction.
- Author
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Knust H, Achermann G, Ballard T, Buettelmann B, Gasser R, Fischer H, Hernandez MC, Knoflach F, Koblet A, Stadler H, Thomas AW, Trube G, and Waldmeier P
- Subjects
- Animals, Anticonvulsants chemical synthesis, Anticonvulsants chemistry, Benzodiazepines chemical synthesis, Benzodiazepines chemistry, Cell Line, Disease Models, Animal, Drug Discovery, Drug Inverse Agonism, GABA-A Receptor Agonists, Humans, Imidazoles chemical synthesis, Imidazoles chemistry, Mice, Protein Binding, Rats, Seizures chemically induced, Seizures drug therapy, Structure-Activity Relationship, Triazoles chemical synthesis, Triazoles chemistry, Anticonvulsants pharmacokinetics, Benzodiazepines pharmacokinetics, Cognition Disorders drug therapy, Imidazoles pharmacokinetics, Receptors, GABA-A metabolism, Triazoles pharmacokinetics
- Abstract
Lead optimisation of the imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepine class led to the identification of two clinical leads [RO4882224 (11) and RO4938581 (44)] functioning as novel potent and selective GABAA alpha5 inverse agonists. The unique pharmacological profiles and optimal pharmacokinetic profiles resulted in in vivo activity in selected cognition models.
- Published
- 2009
- Full Text
- View/download PDF
346. Imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepines as potent and highly selective GABAA alpha5 inverse agonists with potential for the treatment of cognitive dysfunction.
- Author
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Buettelmann B, Ballard TM, Gasser R, Fischer H, Hernandez MC, Knoflach F, Knust H, Stadler H, Thomas AW, and Trube G
- Subjects
- Adjuvants, Anesthesia pharmacology, Animals, Anticonvulsants chemical synthesis, Anticonvulsants pharmacokinetics, Benzodiazepines chemical synthesis, Benzodiazepines pharmacokinetics, Benzodiazepines pharmacology, Cell Line, Drug Inverse Agonism, GABA-A Receptor Agonists, Humans, Memory, Short-Term drug effects, Microsomes, Liver metabolism, Rats, Scopolamine pharmacology, Structure-Activity Relationship, Triazoles chemical synthesis, Triazoles pharmacology, Anticonvulsants chemistry, Benzodiazepines chemistry, Cognition Disorders drug therapy, Receptors, GABA-A metabolism, Triazoles chemistry
- Abstract
In a search for GABAA alpha5 ligands that combine high subtype binding selectivity with a marked inverse agonism imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepines were identified as a promising class. A short tandem reaction allowed rapid access to this chemical series, thereby facilitating rapid SAR generation which guided the optimization process. Two compounds (10e and 11f) were found to be active in an in vivo paradigm for cognitive improvement.
- Published
- 2009
- Full Text
- View/download PDF
347. Discovery of the imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepine scaffold as a novel, potent and selective GABA(A) alpha5 inverse agonist series.
- Author
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Achermann G, Ballard TM, Blasco F, Broutin PE, Büttelmann B, Fischer H, Graf M, Hernandez MC, Hilty P, Knoflach F, Koblet A, Knust H, Kurt A, Martin JR, Masciadri R, Porter RH, Stadler H, Thomas AW, Trube G, and Wichmann J
- Subjects
- Animals, Benzodiazepines chemical synthesis, Benzodiazepines pharmacology, Drug Discovery, Drug Inverse Agonism, GABA-A Receptor Agonists, Humans, Nootropic Agents chemical synthesis, Nootropic Agents pharmacology, Oocytes drug effects, Triazoles chemical synthesis, Triazoles pharmacology, Xenopus laevis, Benzodiazepines chemistry, Nootropic Agents chemistry, Receptors, GABA-A metabolism, Triazoles chemistry
- Abstract
Through iterative design cycles we have discovered a number of novel new classes where the imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepine was deemed the most promising GABA(A) alpha5 inverse agonist class with potential for cognitive enhancement. This class combines a modest subtype binding selectivity with inverse agonism and has the most favourable molecular properties for further lead optimisation towards a central nervous system (CNS) acting medicine.
- Published
- 2009
- Full Text
- View/download PDF
348. Heterotrophic prokaryotic production in ultraoligotrophic alpine karst aquifers and ecological implications.
- Author
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Wilhartitz IC, Kirschner AK, Stadler H, Herndl GJ, Dietzel M, Latal C, Mach RL, and Farnleitner AH
- Subjects
- Archaea isolation & purification, Archaea metabolism, Bacteria isolation & purification, Bacteria metabolism, Carbon Dioxide metabolism, Geologic Sediments microbiology, Leucine metabolism, Principal Component Analysis, Ecosystem, Fresh Water microbiology, Heterotrophic Processes, Plankton metabolism, Water Microbiology
- Abstract
Spring waters from alpine karst aquifers are important drinking water resources. To investigate in situ heterotrophic prokaryotic production and its controlling factors, two different alpine karst springs were studied over two annual cycles. Heterotrophic production in spring water, as determined by [(3)H]leucine incorporation, was extremely low ranging from 0.06 to 6.83 pmol C L(-1) h(-1) (DKAS1, dolomitic-karst-spring) and from 0.50 to 75.6 pmol C L(-1) h(-1) (LKAS2, limestone-karst-spring). Microautoradiography combined with catalyzed reporter deposition-FISH showed that only about 7% of the picoplankton community took up [(3)H]leucine, resulting in generation times of 3-684 days. Principal component analysis, applying hydrological, chemical and biological parameters demonstrated that planktonic heterotrophic production in LKAS2 was governed by the respective hydrological conditions, whereas variations in DKAS1 changed seemingly independent from discharge. Measurements in sediments recovered from LKAS2, DKAS1 and similar alpine karst aquifers (n=12) revealed a 10(6)-fold higher heterotrophic production (average 19 micromol C dm(-3) h(-1)) with significantly lower generation times as compared with the planktonic fraction, highlighting the potential of surface-associated communities to add to self-purification processes. Estimates of the microbially mediated CO(2) in this compartment indicated a possible contribution to karstification.
- Published
- 2009
- Full Text
- View/download PDF
349. Misexpression of Sox9 in mouse limb bud mesenchyme induces polydactyly and rescues hypodactyly mice.
- Author
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Akiyama H, Stadler HS, Martin JF, Ishii TM, Beachy PA, Nakamura T, and de Crombrugghe B
- Subjects
- Animals, Body Patterning, Chondrocytes metabolism, Hedgehog Proteins metabolism, High Mobility Group Proteins metabolism, Homeodomain Proteins metabolism, Limb Buds embryology, Mice, Mice, Knockout, Mice, Transgenic, Mutation, Phenotype, Polydactyly metabolism, SOX9 Transcription Factor, Transcription Factors metabolism, Gene Expression Regulation, Developmental, High Mobility Group Proteins physiology, Limb Buds metabolism, Mesoderm metabolism, Polydactyly genetics, Transcription Factors physiology
- Abstract
Our previous studies have demonstrated the essential roles of the transcription factor Sox9 in the commitment of mesenchymal cells to a chondrogenic cell lineage and in overt chondrogenesis during limb bud development. However, it remains unknown if Sox9 induces chondrogenesis in mesenchyme ectopically in vivo as a master regulator of chondrogenesis. In this study, we first generated mutant mice in which Sox9 was misexpressed in the limb bud mesenchyme. The mutant mouse embryos exhibited polydactyly in limb buds in association with ectopic expression of Sox5 and Sox6 although markers for the different axes of limb bud development showed a normal pattern of expression. Misexpression of Sox9 stimulated cell proliferation in limb bud mesenchyme, suggesting that Sox9 has a role in recruiting mesenchymal cells to mesenchymal condensation. Second, despite the facts that misexpression of Sonic hedgehog (Shh) induces polydactyly in a number of mutant mice and Shh-null mutants have severely defective cartilage elements in limb buds, misexpression of Sox9 did not restore limb bud phenotypes in Shh-null mutants. Rather, there was no expression of Sox9 in digit I of Hoxa13Hd mutant embryos, and Sox9 partially rescued hypodactyly in Hoxa13Hd mutant embryos. These results provide evidence that Sox9 induces ectopic chondrogenesis in mesenchymal cells and strongly suggest that its expression may be regulated by Hox genes during limb bud development.
- Published
- 2007
- Full Text
- View/download PDF
350. HOXA13 directly regulates EphA6 and EphA7 expression in the genital tubercle vascular endothelia.
- Author
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Shaut CA, Saneyoshi C, Morgan EA, Knosp WM, Sexton DR, and Stadler HS
- Subjects
- Animals, Base Sequence, Binding Sites, Cells, Cultured, Endothelium, Vascular metabolism, Genitalia metabolism, Green Fluorescent Proteins genetics, Green Fluorescent Proteins metabolism, Homeodomain Proteins genetics, Homeodomain Proteins metabolism, Mice, Mice, Mutant Strains, Molecular Sequence Data, Promoter Regions, Genetic, Receptor, EphA6 metabolism, Receptor, EphA7 metabolism, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Sequence Homology, Nucleic Acid, Transfection, Endothelium, Vascular embryology, Gene Expression Regulation, Developmental, Genitalia blood supply, Genitalia embryology, Homeodomain Proteins physiology, Receptor, EphA6 genetics, Receptor, EphA7 genetics
- Abstract
Hypospadias, a common defect affecting the growth and closure of the external genitalia, is often accompanied by gross enlargements of the genital tubercle (GT) vasculature. Because Hoxa13 homozygous mutant mice also exhibit hypospadias and GT vessel expansion, we examined whether genes playing a role in angiogenesis exhibit reduced expression in the GT. From this analysis, reductions in EphA6 and EphA7 were detected. Characterization of EphA6 and EphA7 expression in the GT confirmed colocalization with HOXA13 in the GT vascular endothelia. Analysis of the EphA6 and EphA7 promoter regions revealed a series of highly conserved cis-regulatory elements bound by HOXA13 with high affinity. GT chromatin immunoprecipitation confirmed that HOXA13 binds these gene-regulatory elements in vivo. In vitro, HOXA13 activates gene expression through the EphA6 and EphA7 gene-regulatory elements. Together these findings indicate that HOXA13 directly regulates EphA6 and EphA7 in the developing GT and identifies the GT vascular endothelia as a novel site for HOXA13-dependent expression of EphA6 and EphA7.
- Published
- 2007
- Full Text
- View/download PDF
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