Publications by authors named "Kraus Y"

Exposure therapy is an efficient treatment for pathological anxiety, yet its underlying mechanisms are not fully understood. Prediction error models suggest that optimizing the violation of threat-related expectancies improves treatment outcomes, however, causal evidence is still sparse. The aim of the current study was therefore to provide causal evidence for the influence of the extent of expectancy violations on extinction retention using a novel virtual reality fear conditioning paradigm.

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Azobenzene analogues of the tubulin polymerisation inhibitor combretastatin A4 (PSTs) were previously developed to optically control microtubule dynamics in living systems, with subsecond response time and single-cell spatial precision, by reversible photoswitching of their bioactivity with near-UV/visible light. First-generation PSTs were sufficiently potent and photoswitchable for use in live cells and embryos. However, the link between their seconds-scale and hours-scale bioactivity remained untested.

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The complex morphology of neurons requires precise control of their microtubule cytoskeleton. This is achieved by microtubule-associated proteins (MAPs) that regulate the assembly and stability of microtubules, and transport of molecules and vesicles along them. While many of these MAPs function in all cells, some are specifically or predominantly involved in regulating microtubules in neurons.

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Pulmonary hypertension (PH) is the most severe complication in preterm infants with bronchopulmonary dysplasia (BPD) and associated with significant mortality. Diagnostic and treatment strategies, however, still lack standardization. By the use of a survey study (PH in BPD), we assessed clinical practice (diagnosis, treatment, follow-up) in preterm infants with early postnatal persistent pulmonary hypertension of the newborn (PPHN) as well as at risk for or with established BPD-associated PH between 06/2018 and 10/2020 in two-thirds of all German perinatal centers with >70 very low birthweight infants/year including their cardiology departments and outpatient units.

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Renal involvement represents the major long-term morbidity associated with IgA vasculitis (IgAV). Our aim was to evaluate clinical characteristics and long-term renal outcomes of IgAV in pediatrics and adults comparing to IgA nephropathy (IgAN). Our retrospective study included children and adults with IgAV and IgAN patients, admitted in a 13-year period (2007-2019) to rheumatology clinics and in hospital pediatric and internal medicine departments.

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Background: Pulmonary vascular disease (PVD) affects the majority of preterm neonates with bronchopulmonary dysplasia (BPD) and significantly determines long-term mortality through undetected progression into pulmonary hypertension. Our objectives were to associate characteristics of pulmonary artery (PA) flow and cardiac function with BPD-associated PVD near term using advanced magnetic resonance imaging (MRI) for improved risk stratification.

Methods: Preterms <32 weeks postmenstrual age (PMA) with/without BPD were clinically monitored including standard echocardiography and prospectively enrolled for 3 T MRI in spontaneous sleep near term (AIRR (Attention to Infants at Respiratory Risks) study).

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Very preterm infants are at high risk for suboptimal nutrition in the first weeks of life leading to insufficient weight gain and complications arising from metabolic imbalances such as insufficient bone mineral accretion. We investigated the use of a novel set of standardized parenteral nutrition (PN; MUC PREPARE) solutions regarding improving nutritional intake, accelerating termination of parenteral feeding, and positively affecting growth in comparison to individually prescribed and compounded PN solutions. We studied the effect of MUC PREPARE on macro- and micronutrient intake, metabolism, and growth in 58 very preterm infants and compared results to a historic reference group of 58 very preterm infants matched for clinical characteristics.

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Novel photoswitches offering features complementary to the well-established azobenzenes are increasingly driving high-precision research in cellular photopharmacology. Styrylthiazolium (StyTz) and styrylbenzothiazolium (StyBtz) are cellularly untested /-isomerisation photoswitches which are nearly isosteric to azobenzenes, but have distinct properties: including 60 nm red-shifted π → π* absorption, self-reporting fluorescence, → relaxation on typical biological timescales, and decent solubility (positive charge). We tested StyTz and StyBtz for their potential as photopharmaceutical scaffolds, by applying them to photocontrol microtubule dynamics.

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Background: (Scyphozoa, Cnidaria) is an emblematic species of the jellyfish. Currently, it is an emerging model of Evo-Devo for studying evolution and molecular regulation of metazoans' complex life cycle, early development, and cell differentiation. For , the genome was sequenced, the molecular cascades involved in the life cycle transitions were characterized, and embryogenesis was studied on the level of gross morphology.

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CO in the atmosphere is a major contributor to global warming but at the same time it has the potential to be a carbon source for advanced biomanufacturing. To utilize CO, carbonic anhydrase has been identified as a key enzyme. Furthermore, attempts have been made to accelerate the sequestration via pressure.

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Background: In almost all metazoans examined to this respect, the axial patterning system based on canonical Wnt (cWnt) signaling operates throughout the course of development. In most metazoans, gastrulation is polar, and embryos develop morphological landmarks of axial polarity, such as blastopore under control/regulation from cWnt signaling. However, in many cnidarian species, gastrulation is morphologically apolar.

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In animals, body axis patterning is based on the concentration-dependent interpretation of graded morphogen signals, which enables correct positioning of the anatomical structures. The most ancient axis patterning system acting across animal phyla relies on β-catenin signaling, which directs gastrulation, and patterns the main body axis. However, within Bilateria, the patterning logic varies significantly between protostomes and deuterostomes.

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Optically controlled chemical reagents, termed "photopharmaceuticals," are powerful tools for precise spatiotemporal control of proteins particularly when genetic methods, such as knockouts or optogenetics are not viable options. However, current photopharmaceutical scaffolds, such as azobenzenes are intolerant of GFP/YFP imaging and are metabolically labile, posing severe limitations for biological use. We rationally designed a photoswitchable "SBT" scaffold to overcome these problems, then derivatized it to create exceptionally metabolically robust and fully GFP/YFP-orthogonal "SBTub" photopharmaceutical tubulin inhibitors.

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The cnidarian "planula" larva shows radial symmetry around a polarized, oral-aboral, body axis and comprises two epithelia cell layers, ectodermal and endodermal. This simple body plan is set up during gastrulation, a process which proceeds by a variety of modes amongst the diverse cnidarian species. In the hydrozoan laboratory model Clytia hemisphaerica, gastrulation involves a process termed unipolar cell ingression, in which the endoderm derives from mass ingression of individual cells via a process of epithelial-mesenchymal transition (EMT) around the future oral pole of an epithelial embryo.

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Small molecule inhibitors are prime reagents for studies in microtubule cytoskeleton research, being applicable across a range of biological models and not requiring genetic engineering. However, traditional chemical inhibitors cannot be experimentally applied with spatiotemporal precision suiting the length and time scales inherent to microtubule-dependent cellular processes. We have synthesised photoswitchable paclitaxel-based microtubule stabilisers, whose binding is induced by photoisomerisation to their metastable state.

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We describe a molecular characterization of the interaction between the cancer-related proteins WWOX and p73. This interaction is mediated by the first of two WW domains (WW1) of WWOX and a PPXY-motif-containing region in p73. While phosphorylation of Tyr33 of WWOX and association with p73 are known to affect apoptotic activity, the quantitative effect of phosphorylation on this specific interaction is determined here for the first time.

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Hemithioindigo is a promising molecular photoswitch that has only recently been applied as a photoswitchable pharmacophore for control over bioactivity in cellulo. Uniquely, in contrast to other photoswitches that have been applied to biology, the pseudosymmetric hemithioindigo scaffold has allowed the creation of both dark-active and lit-active photopharmaceuticals for the same binding site by a priori design. However, the potency of previous hemithioindigo photopharmaceuticals has not been optimal for their translation to other biological models.

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In Cnidaria, modes of gastrulation to produce the two body layers vary greatly between species. In the hydrozoan species Clytia hemisphaerica gastrulation involves unipolar ingression of presumptive endoderm cells from an oral domain of the blastula, followed by migration of these cells to fill the blastocoel with concomitant narrowing of the gastrula and elongation along the oral-aboral axis. We developed a 2D computational boundary model capable of simulating the morphogenetic changes during embryonic development from early blastula stage to the end of gastrulation.

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We here report the discovery of isoquinoline-based biaryls as a new scaffold for colchicine domain tubulin inhibitors. Colchicinoid inhibitors offer highly desirable cytotoxic and vascular disrupting bioactivities, but their further development requires improving in vivo robustness and tolerability: properties that both depend on the scaffold structure employed. We have developed isoquinoline-based biaryls as a novel scaffold for high-potency tubulin inhibitors, with excellent robustness, druglikeness, and facile late-stage structural diversification, accessible through a tolerant synthetic route.

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Morphogenesis is a shape-building process during development of multicellular organisms. During this process, the establishment and modulation of cell-cell contacts play an important role. Cadherins, the major cell adhesion molecules, form adherens junctions connecting epithelial cells.

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At the polyp stage, most hydrozoan cnidarians form highly elaborate colonies with a variety of branching patterns, which makes them excellent models for studying the evolutionary mechanisms of body plan diversification. At the same time, molecular mechanisms underlying the robust patterning of the architecturally complex hydrozoan colonies remain unexplored. Using non-model hydrozoan Dynamena pumila we showed that the key components of the Wnt/β-catenin (cWnt) pathway (β-catenin, TCF) and the cWnt-responsive gene, brachyury 2, are involved in specification and patterning of the developing colony shoots.

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Druglike small molecules with photoswitchable bioactivity-photopharmaceuticals-allow biologists to perform studies with exquisitely precise and reversible, spatial and temporal control over critical biological systems inaccessible to genetic manipulation. The photoresponsive pharmacophores disclosed have been almost exclusively azobenzenes, which has limited the structural and substituent scope of photopharmacology. More detrimentally, for azobenzene reagents, it is not researchers' needs for adapted experimental tools, but rather protein binding site sterics, that typically force whether the trans (dark) or cis (lit) isomer is the more bioactive.

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Progress of Evo-Devo requires broad phylogenetic sampling providing the data for comparative analysis as well as new objects suitable for experimental investigation. Representatives of the early-branching animal phylum Cnidaria and particularly hydrozoans draw great attention due to the high diversity of embryonic and post-embryonic development and life-cycles in general. Most detailed studies on embryonic development in hydrozoans were performed on the species shedding their gametes with subsequent embryo development in the water column.

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Epithelial folding (EF) is a fundamental morphogenetic process that can be observed in the development of many organisms ranging from metazoans to green algae. Being early branching metazoans, cnidarians represent the best models to study evolutionarily conserved morphogenetic processes, including EF. Hydrozoa is the most evolutionary advanced group of the phylum Cnidaria.

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Article Synopsis
  • - Robust morphogenetic events are crucial for animal embryogenesis, but different species within a phylum can follow a broader range of developmental paths than what is seen in typical development.
  • - Using microsurgery and transgenic reporter gene expression, researchers demonstrated that dissociated embryonic cells of the sea anemone can adopt an alternative development route in response to new conditions.
  • - These cell aggregates depend on Wnt signals from the original organizer and exhibit significant plasticity, allowing ectodermal cells to transform into endoderm, indicating that new developmental trajectories can arise more easily when embryonic cells are highly adaptable.
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