4,071 results on '"Schumacher A"'
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2. The Chemicals between Us--First Results of the Cluster Analyses on Anatomy Embalming Procedures in the German-Speaking Countries
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Kerner, Alexander Michael, Biedermann, Uta, Bräuer, Lars, Caspers, Svenja, Doll, Sara, Engelhardt, Maren, Filler, Timm J., Ghebremedhin, Estifanos, Gundlach, Stefanie, Hayn-Leichsenring, Gregor U., Heermann, Stephan, Hettwer-Steeger, Ingrid, Hiepe, Laura, Hirt, Bernhard, Hirtler, Lena, Hörmann, Rom, Kulisch, Christoph, Lange, Tobias, Leube, Rudolf, Meuser, Annika Hela, Müller-Gerbl, Magdalena, Nassenstein, Christina, Neckel, Peter H., Nimtschke, Ute, Paulsen, Friedrich, Prescher, Andreas, Pretterklieber, Michael, Schliwa, Stefanie, Schmidt, Katja, Schmiedl, Andreas, Schomerus, Christof, Schulze-Tanzil, Gundula, Schumacher, Udo, Schumann, Sven, Spindler, Volker, Streicher, Johannes, Tschernig, Thomas, Unverzagt, Axel, Valentiner, Ursula, Viebahn, Christoph, Wedel, Thilo, Weigner, Janet, Weninger, Wolfgang J., Westermann, Jürgen, Weyers, Imke, Waschke, Jens, and Hammer, Niels
- Abstract
Hands-on courses utilizing preserved human tissues for educational training offer an important pathway to acquire basic anatomical knowledge. Owing to the reevaluation of formaldehyde limits by the European Commission, a joint approach was chosen by the German-speaking anatomies in Europe (Germany, Austria, Switzerland) to find commonalities among embalming protocols and infrastructure. A survey comprising 537 items was circulated to all anatomies in German-speaking Europe. Clusters were established for "ethanol"-, formaldehyde-based ("FA"), and "other" embalming procedures, depending on the chemicals considered the most relevant for each protocol. The logistical framework, volumes of chemicals, and infrastructure were found to be highly diverse between the groups and protocols. Formaldehyde quantities deployed per annum were three-fold higher in the "FA" (223 L/a) compared to the "ethanol" (71.0 L/a) group, but not for "other" (97.8 L/a), though the volumes injected per body were similar. "FA" was strongly related to table-borne air ventilation and total fixative volumes =1000 L. "Ethanol" was strongly related to total fixative volumes >1000 L, ceiling- and floor-borne air ventilation, and explosion-proof facilities. Air ventilation was found to be installed symmetrically in the mortuary and dissection facilities. Certain predictors exist for the interplay between the embalming used in a given infrastructure and technical measures. The here-established cluster analysis may serve as decision supportive tool when considering altering embalming protocols or establishing joint protocols between institutions, following a best practice approach to cater toward best-suited tissue characteristics for educational purposes, while simultaneously addressing future demands on exposure limits.
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- 2023
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3. Quadruple[6]Helicene Featuring Pyrene Core: Unraveling Contorted Aromatic Core with Larger Effective Conjugation
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Christopher Wallerius, Otgonbayar Erdene-Ochir, Eva Van Doeselar, Ronald Alle, Anh Tu Nguyen, Marvin F. Schumacher, Arne Lützen, Klaus Meerholz, and Sai Ho Pun
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Chemistry ,QD1-999 - Published
- 2024
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4. Designing Authentic Learning Environments in Chemistry Lessons: Paving the Way in Pre-Service Teacher Education
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Schumacher, Andrea and Reiners, Christiane S.
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Authenticity has recently become a popular term in science education. A study focusing on authenticity in the sense of making chemistry lessons better resemble chemistry practice is carried out at the University of Cologne in the Institute of Chemical Education, where prospective chemistry teachers are trained. In the long run an innovative module shall be developed, which challenges teacher students' pre-conceptions about characteristics of chemistry practice and supports them in translating their conceptions into authentic learning environments. This paper presents the first part of the project in which course elements to stimulate reflection on students' attitudes were evaluated. Moreover the students were given an opportunity for teacher students to create a practical activity for pupils in order to detect aspects in which the students need more support, for example possible ways for this transformation or more experience with inquiry-based learning.
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- 2013
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5. Chromate Affects Gene Expression and DNA Methylation in Long-Term In Vitro Experiments in A549 Cells
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Franziska Fischer, Sandra Stößer, Lisa Wegmann, Eva Veh, Tatjana Lumpp, Marlene Parsdorfer, Paul Schumacher, and Andrea Hartwig
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chromate ,epigenetic ,DNA methylation ,long-term exposure ,gene expression profiles ,oxidative stress ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Chromate has been shown to dysregulate epigenetic mechanisms such as DNA methylation, leading to changes in gene expression and genomic instability. However, most in vitro studies are limited to short incubation periods, although chronic exposure may be more relevant for both environmental and occupational exposure. In this study, human adenocarcinoma A549 cells were treated with 1, 2 or 5 µM chromate for 24 h and compared with incubations with 0.2, 0.5 or 1 µM chromate for 1 to 5 weeks. Chromium accumulated in a pronounced time- and concentration-dependent manner after short-term treatment, whereas a plateau of intracellular chromium content was observed after long-term treatment. While short-term treatment induced a G2 arrest of the cell cycle, this effect was not observed after long-term treatment at lower concentrations. The opposite was observed for global DNA methylation: while short-term treatment showed no effect of chromate, significant dose-dependent hypomethylation was observed in the long-term experiments. Time-dependent effects were also observed in a high-throughput RT-qPCR gene expression analysis, particularly in genes related to the inflammatory response and DNA damage response. Taken together, the results suggest specific differences in toxicity profiles when comparing short-term and long-term exposure to chromate in A549 cells.
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- 2024
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6. Unraveling surface and bulk dynamics of iron(III) molybdate during oxidative dehydrogenation using operando and transient spectroscopies
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Leon Schumacher, Mariusz Radtke, Jan Welzenbach, and Christian Hess
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Chemistry ,QD1-999 - Abstract
Abstract Iron(III) molybdate (Fe2(MoO4)3) is a commercial catalyst for the oxidative dehydrogenation (ODH) of methanol, but it has recently been shown to be relevant for other substrates as well. Despite its commercial use, a detailed mechanistic understanding of Fe2(MoO4)3 catalysts at the surface and in the bulk has been lacking, largely hampered by the lack of suitable spectroscopic methods, directly applicable under reaction conditions. Using propane ODH as an example, we highlight the potential of operando Raman and impedance spectroscopy combined with transient IR spectroscopy, to identify surface active sites and monitor the hydrogen transfer and oxygen dynamics. By comparison with the behavior of reference compounds (MoO3, MoOx/Fe2O3) a mechanistic model is proposed. The presence of iron greatly influences the reactivity behavior via oxygen diffusion but is moderated in its oxidative capacity by surface MoOx. Our approach directly elucidates fundamental properties of Fe2(MoO4)3 of general importance to selective oxidation catalysis.
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- 2023
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7. An archaeal lid-containing feruloyl esterase degrades polyethylene terephthalate
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Pablo Perez-Garcia, Jennifer Chow, Elisa Costanzi, Marno Gurschke, Jonas Dittrich, Robert F. Dierkes, Rebecka Molitor, Violetta Applegate, Golo Feuerriegel, Prince Tete, Dominik Danso, Stephan Thies, Julia Schumacher, Christopher Pfleger, Karl-Erich Jaeger, Holger Gohlke, Sander H. J. Smits, Ruth A. Schmitz, and Wolfgang R. Streit
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Chemistry ,QD1-999 - Abstract
Abstract Polyethylene terephthalate (PET) is a commodity polymer known to globally contaminate marine and terrestrial environments. Today, around 80 bacterial and fungal PET-active enzymes (PETases) are known, originating from four bacterial and two fungal phyla. In contrast, no archaeal enzyme had been identified to degrade PET. Here we report on the structural and biochemical characterization of PET46 (RLI42440.1), an archaeal promiscuous feruloyl esterase exhibiting degradation activity on semi-crystalline PET powder comparable to IsPETase and LCC (wildtypes), and higher activity on bis-, and mono-(2-hydroxyethyl) terephthalate (BHET and MHET). The enzyme, found by a sequence-based metagenome search, is derived from a non-cultivated, deep-sea Candidatus Bathyarchaeota archaeon. Biochemical characterization demonstrated that PET46 is a promiscuous, heat-adapted hydrolase. Its crystal structure was solved at a resolution of 1.71 Å. It shares the core alpha/beta-hydrolase fold with bacterial PETases, but contains a unique lid common in feruloyl esterases, which is involved in substrate binding. Thus, our study widens the currently known diversity of PET-hydrolyzing enzymes, by demonstrating PET depolymerization by a plant cell wall-degrading esterase.
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- 2023
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8. Simulation-Based Prediction of the Cold Start Behavior of Gerotor Pumps for Precise Design of Electric Oil Pumps
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Sven Schumacher, Ralf Stetter, Markus Till, Nicolas Laviolette, Benoît Algret, and Stephan Rudolph
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model-based design ,electric oil pumps ,gerotor pumps ,virtual validation ,automotive fluid systems ,pump cold start behavior ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The development of electric gerotor pumps is a complex multiphysical optimization problem. To develop optimal systems, accurate simulation models are required to increase digital reliability. An important challenge is the accurate prediction of the pump behavior for extreme temperatures in automotive applications from −40 °C to 110 °C, where the viscosity of the fluid changes significantly. Therefore, simulation-based methods (numerical methods for calculating viscous friction) were developed and validated by measurements, including climatic chamber tests. The results show a strong correlation between simulated and measured performance characteristics, especially in terms of volumetric flow rate (<5%), pump torque and efficiency (<7%) at different temperature and viscosity conditions over a wide speed range (1000–5000 rpm) and different system pressures (0.5–5 bar). A novel method for simulating the cold start behavior of pumps (journal bearing approach for outer gear in pump housing) was introduced and validated by measurements. The methods presented significantly reduce the need for physical testing and accelerate the development process, as the pump behavior at each operating point can be accurately predicted before a hardware prototype is built. This improves the understanding of gerotor pump characteristics and provides insights to further improve the model-based development of electric oil pumps for the automotive industry.
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- 2024
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9. GRT-X Stimulates Dorsal Root Ganglia Axonal Growth in Culture via TSPO and Kv7.2/3 Potassium Channel Activation
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Léa El Chemali, Suzan Boutary, Song Liu, Guo-Jun Liu, Ryan J. Middleton, Richard B. Banati, Gregor Bahrenberg, Rainer Rupprecht, Michael Schumacher, and Liliane Massaad-Massade
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TSPO ,peripheral benzodiazepine receptor ,potassium channels ,Kv7.2/3 ,KCNQ2/3 ,GRT-X ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
GRT-X, which targets both the mitochondrial translocator protein (TSPO) and the Kv7.2/3 (KCNQ2/3) potassium channels, has been shown to efficiently promote recovery from cervical spine injury. In the present work, we investigate the role of GRT-X and its two targets in the axonal growth of dorsal root ganglion (DRG) neurons. Neurite outgrowth was quantified in DRG explant cultures prepared from wild-type C57BL6/J and TSPO-KO mice. TSPO was pharmacologically targeted with the agonist XBD173 and the Kv7 channels with the activator ICA-27243 and the inhibitor XE991. GRT-X efficiently stimulated DRG axonal growth at 4 and 8 days after its single administration. XBD173 also promoted axonal elongation, but only after 8 days and its repeated administration. In contrast, both ICA27243 and XE991 tended to decrease axonal elongation. In dissociated DRG neuron/Schwann cell co-cultures, GRT-X upregulated the expression of genes associated with axonal growth and myelination. In the TSPO-KO DRG cultures, the stimulatory effect of GRT-X on axonal growth was completely lost. However, GRT-X and XBD173 activated neuronal and Schwann cell gene expression after TSPO knockout, indicating the presence of additional targets warranting further investigation. These findings uncover a key role of the dual mode of action of GRT-X in the axonal elongation of DRG neurons.
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- 2024
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10. Impaired Tertiary Dentin Secretion after Shallow Injury in Tgfbr2-Deficient Dental Pulp Cells Is Rescued by Extended CGRP Signaling
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Monica Stanwick, Fatma Fenesha, Ahmed Hamid, Khushroop Kang, Dane Kanniard, Irene Kim, Nicholas Mandarano, Fernanda L. Schumacher, and Sarah B. Peters
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transforming growth factor beta ,calcitonin gene-related peptide ,tertiary dentin ,neuropeptide ,dental pulp cells ,pulp biology ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The transforming growth factor β (TGFβ) superfamily is a master regulator of development, adult homeostasis, and wound repair. Dysregulated TGFβ signaling can lead to cancer, fibrosis, and musculoskeletal malformations. We previously demonstrated that TGFβ receptor 2 (Tgfbr2) signaling regulates odontoblast differentiation, dentin mineralization, root elongation, and sensory innervation during tooth development. Sensory innervation also modulates the homeostasis and repair response in adult teeth. We hypothesized that Tgfbr2 regulates the neuro-pulpal responses to dentin injury. To test this, we performed a shallow dentin injury with a timed deletion of Tgfbr2 in the dental pulp mesenchyme of mice and analyzed the levels of tertiary dentin and calcitonin gene-related peptide (CGRP) axon sprouting. Microcomputed tomography imaging and histology indicated lower dentin volume in Tgfbr2cko M1s compared to WT M1s 21 days post-injury, but the volume was comparable by day 56. Immunofluorescent imaging of peptidergic afferents demonstrated that the duration of axon sprouting was longer in injured Tgfbr2cko compared to WT M1s. Thus, CGRP+ sensory afferents may provide Tgfbr2-deficient odontoblasts with compensatory signals for healing. Harnessing these neuro-pulpal signals has the potential to guide the development of treatments for enhanced dental healing and to help patients with TGFβ-related diseases.
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- 2024
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11. On the RE2TiAl3 (RE = Y, Gd–Tm, Lu) Series—The First Aluminum Representatives of the Rhombohedral Mg2Ni3Si Type Structure
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Elias C. J. Gießelmann, Stefan Engel, Israa M. El Saudi, Lars Schumacher, Mathis Radzieowski, Josef Maximilian Gerdes, and Oliver Janka
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intermetallics ,rare-earth elements ,titanium ,aluminum ,physical properties ,Chemistry ,QD1-999 - Abstract
Several ternary rare-earth metals containing titanium aluminum intermetallics in the RE2TiAl3 series (RE = Y, Gd–Lu) have been synthesized from the elements using arc-melting techniques. All compounds crystallize in the trigonal crystal system with rhombohedral space group R3m (Z = 3) and lattice parameters ranging between a = 582–570 and c = 1353–1358 pm. They adopt the Mg2Ni3Si-type structure, which is an ordered superstructure of the cubic Laves phase MgCu2 and has been observed for Al intermetallics for the first time. Tetrahedral [TiAl3] entities that are connected over all corners form a network where the empty [TiAl3] tetrahedra exhibit a full Ti/Al ordering based on the single crystal results. The Al atoms are arranged into 63 Kagomé nets, while the Ti atoms connect these nets over the triangular units. In the cavities of this three-dimensional arrangement, the RE cations can be found forming a distorted diamond-type substructure. Magnetic measurements revealed that Y2TiAl3 and Lu2TiAl3 are Pauli paramagnetic substances, in line with the metallic character. The other compounds exhibit paramagnetism with antiferromagnetic ordering at a maximum Néel temperature of TN = 26.1(1) K for Gd2TiAl3.
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- 2023
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12. The Evolving Landscape of Neuroscience Therapeutics: an Interplay of Multiple Modalities
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Hendrik Knoetgen, Torsten Schindler, Felix F. Schumacher, Antonia F. Stepan, Alain C. Tissot, and Jaclyn I. Wamsteeker Cusulin
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Chemistry ,QD1-999 - Published
- 2024
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13. Soluble Neuropilin-1 Is Elevated in Sepsis and Correlates with Organ Dysfunction and Long-Term Mortality in Critical Illness
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Philipp Hohlstein, Eileen Schumacher, Samira Abu Jhaisha, Jule K. Adams, Maike R. Pollmanns, Carolin V. Schneider, Karim Hamesch, Katarina Horvathova, Theresa H. Wirtz, Frank Tacke, Christian Trautwein, Ralf Weiskirchen, and Alexander Koch
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Neuropilin-1 ,intensive care unit ,critical illness ,sepsis ,human ,inflammation ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Critical illness and sepsis may cause organ failure and are recognized as mortality drivers in hospitalized patients. Neuropilin-1 (NRP-1) is a multifaceted transmembrane protein involved in the primary immune response and is expressed in immune cells such as T and dendritic cells. The soluble form of NRP-1 (sNRP-1) acts as an antagonist to NRP-1 by scavenging its ligands. The aim of this study was to determine the value of sNRP-1 as a biomarker in critical illness and sepsis. We enrolled 180 critically ill patients admitted to a medical intensive care unit and measured serum sNRP-1 concentrations at admission, comparing them to 48 healthy individuals. Critically ill and septic patients showed higher levels of sNRP-1 compared to healthy controls (median of 2.47 vs. 1.70 nmol/L, p < 0.001). Moreover, sNRP-1 was also elevated in patients with sepsis compared to other critical illness (2.60 vs. 2.13 nmol/L, p = 0.01), irrespective of disease severity or organ failure. In critically ill patients, sNRP-1 is positively correlated with markers of kidney and hepatic dysfunction. Most notably, critically ill patients not surviving in the long term (one year after admission) showed higher concentrations of sNRP-1 at the time of ICU admission (p = 0.036), with this association being dependent on the presence of organ failure. Critically ill and septic patients exhibit higher serum concentrations of circulating sNRP-1, which correlates to organ failure, particularly hepatic and kidney dysfunction.
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- 2024
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14. Formation of DNA Adducts by 1-Methoxy-3-indolylmethylalcohol, a Breakdown Product of a Glucosinolate, in the Mouse: Impact of the SULT1A1 Status—Wild-Type, Knockout or Humanised
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Hansruedi Glatt, Sarah Yasmin Weißenberg, Anke Ehlers, Alfonso Lampen, Albrecht Seidel, Fabian Schumacher, Wolfram Engst, and Walter Meinl
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Brassica vegetable ,broccoli ,DNA adducts ,glucosinolates ,neoglucobrassicin ,N-methoxy-indole-3-carbinol ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
We previously found that feeding rats with broccoli or cauliflower leads to the formation of characteristic DNA adducts in the liver, intestine and various other tissues. We identified the critical substances in the plants as 1-methoxy-3-indolylmethyl (1-MIM) glucosinolate and its degradation product 1-MIM-OH. DNA adduct formation and the mutagenicity of 1-MIM-OH in cell models were drastically enhanced when human sulfotransferase (SULT) 1A1 was expressed. The aim of this study was to clarify the role of SULT1A1 in DNA adduct formation by 1-MIM-OH in mouse tissues in vivo. Furthermore, we compared the endogenous mouse Sult1a1 and transgenic human SULT1A1 in the activation of 1-MIM-OH using genetically modified mouse strains. We orally treated male wild-type (wt) and Sult1a1-knockout (ko) mice, as well as corresponding lines carrying the human SULT1A1-SULT1A2 gene cluster (tg and ko-tg), with 1-MIM-OH. N2-(1-MIM)-dG and N6-(1-MIM)-dA adducts in DNA were analysed using isotope-dilution UPLC-MS/MS. In the liver, caecum and colon adducts were abundant in mice expressing mouse and/or human SULT1A1, but were drastically reduced in ko mice (1.2–10.6% of wt). In the kidney and small intestine, adduct levels were high in mice carrying human SULT1A1-SULT1A2 genes, but low in wt and ko mice (1.8–6.3% of tg-ko). In bone marrow, adduct levels were very low, independently of the SULT1A1 status. In the stomach, they were high in all four lines. Thus, adduct formation was primarily controlled by SULT1A1 in five out of seven tissues studied, with a strong impact of differences in the tissue distribution of mouse and human SULT1A1. The behaviour of 1-MIM-OH in these models (levels and tissue distribution of DNA adducts; impact of SULTs) was similar to that of methyleugenol, classified as “probably carcinogenic to humans”. Thus, there is a need to test 1-MIM-OH for carcinogenicity in animal models and to study its adduct formation in humans consuming brassicaceous foodstuff.
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- 2024
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15. The Role of Neutral Sphingomyelinase-2 (NSM2) in the Control of Neutral Lipid Storage in T Cells
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Rebekka Schempp, Janna Eilts, Marie Schöl, Maria Fernanda Grijalva Yépez, Agnes Fekete, Dominik Wigger, Fabian Schumacher, Burkhard Kleuser, Marco van Ham, Lothar Jänsch, Markus Sauer, and Elita Avota
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neutral sphingomyelinase-2 (NSM2) ,lipid droplet (LD) ,plasma membrane (PM) ,diacylglycerol (DAG) ,cholesteryl ester (CE) ,triacylglycerol (TAG) ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The accumulation of lipid droplets (LDs) and ceramides (Cer) is linked to non-alcoholic fatty liver disease (NAFLD), regularly co-existing with type 2 diabetes and decreased immune function. Chronic inflammation and increased disease severity in viral infections are the hallmarks of the obesity-related immunopathology. The upregulation of neutral sphingomyelinase-2 (NSM2) has shown to be associated with the pathology of obesity in tissues. Nevertheless, the role of sphingolipids and specifically of NSM2 in the regulation of immune cell response to a fatty acid (FA) rich environment is poorly studied. Here, we identified the presence of the LD marker protein perilipin 3 (PLIN3) in the intracellular nano-environment of NSM2 using the ascorbate peroxidase APEX2-catalyzed proximity-dependent biotin labeling method. In line with this, super-resolution structured illumination microscopy (SIM) shows NSM2 and PLIN3 co-localization in LD organelles in the presence of increased extracellular concentrations of oleic acid (OA). Furthermore, the association of enzymatically active NSM2 with isolated LDs correlates with increased Cer levels in these lipid storage organelles. NSM2 enzymatic activity is not required for NSM2 association with LDs, but negatively affects the LD numbers and cellular accumulation of long-chain unsaturated triacylglycerol (TAG) species. Concurrently, NSM2 expression promotes mitochondrial respiration and fatty acid oxidation (FAO) in response to increased OA levels, thereby shifting cells to a high energetic state. Importantly, endogenous NSM2 activity is crucial for primary human CD4+ T cell survival and proliferation in a FA rich environment. To conclude, our study shows a novel NSM2 intracellular localization to LDs and the role of enzymatically active NSM2 in metabolic response to enhanced FA concentrations in T cells.
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- 2024
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16. Effect of Long-Term Low-Dose Arsenic Exposure on DNA Methylation and Gene Expression in Human Liver Cells
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Sandra Stößer, Tatjana Lumpp, Franziska Fischer, Sarah Gunesch, Paul Schumacher, and Andrea Hartwig
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arsenic ,DNA methyltransferase ,gene expression profiles ,hypomethylation ,cytotoxicity ,cell cycle ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Millions of people around the world are exposed to elevated levels of arsenic through food or drinking water. Epidemiological studies have linked chronic arsenic exposure to an increased risk of several cancers, cardiovascular disease, central nervous system neuropathies, and genotoxic as well as immunotoxic effects. In addition to the induction of oxidative stress and inhibition of DNA repair processes, epigenetic effects, including altered DNA methylation patterns resulting in aberrant gene expression, may contribute to carcinogenicity. However, the underlying mechanisms by which chronic micromolar concentrations of arsenite affect the methylation status of DNA are not fully understood. In this study, human HepG2 hepatocarcinoma cells were treated with 0.5–10 μM sodium arsenite for 24 h, 10, or 20 days. During these periods, the effects on global DNA methylation, cell cycle phase distribution, and gene expression were investigated. While no impact on DNA methylation was seen after short-term exposure, global hypomethylation was observed at both long-term exposure periods, with concomitant induction of the DNA methyltransferase genes DNMT1 and DNMT3B, while DNMT3A was slightly down-regulated. Pronounced time- and concentration-dependent effects were also seen in the case of genes involved in DNA damage response and repair, inflammation, oxidative stress response, and metal homeostasis. These results suggest that chronic low-dose arsenite exposure can lead to global hypomethylation. As an underlying mechanism, the consistent down-regulation of DNA methyltransferase genes could be excluded; alternatively, interactions at the protein level could play an important role.
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- 2023
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17. Recent Approaches in Transition Metal-Catalyzed Chalcogenative Heteroannulation of Alkenes and Alkynes
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Elba L. Gutterres, Thiago Anjos, Felipe B. Santos, Pamela T. Bandeira, Filipe Penteado, and Ricardo F. Schumacher
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catalysis ,cyclization reaction ,heterocycles ,organochalcogen ,transition metal ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
Organochalcogen-bearing heterocycles are important scaffolds in compounds under the spotlight of scientific interest in optoelectronic fields and for biological applications. The use of transition metals has been a versatile and reliable way to carry out the synthesis of these molecules efficiently, delivering products in high yields and with a wide functional diversity. In the last 10 years, many classes of heterocycles have been synthesized under the cyclization reaction of acyclic alkenes and alkynes with the incorporation of a chalcogen atom on its structure. Transition metal catalysts including Cu, Co, Pd, Ni, In, Ag, and Fe salts have been used in the development of new methodologies, the expansion of substrate scope, and mechanistic studies. This review provides an overview of these recent approaches with the aim of being a useful resource for interested researchers in this area.
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- 2023
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18. Key technology to non-aqueous and multi-step biocatalysis: Pickering emulsions
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Marion B. Ansorge-Schumacher and Christoph Plikat
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multi-phase biocatalysis ,multi-step biocatalysis ,Pickering emulsion ,phase composition ,materials ,particle choice ,Chemistry ,QD1-999 - Abstract
Considering the importance of biocatalysis in chemical synthesis, technologies allowing full exploitation of its potential are urgently wanted. Eleven years ago, our team proposed Pickering emulsions as a concept to overcome the severe restrictions set by the general requirement for the presence of water. In this brief perspective, we demonstrate that the insights into bioactive Pickering emulsions gathered meanwhile strongly designate it a key technology to non-aqueous and multi-step biocatalysis. Mainly, this relates to the extensive compatibility of this system with different solvents, materials, biocatalysts, reactions and demands on productive use. We here give a brief overview of the most relevant details, including recent results from our own research.
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- 2022
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19. Estimation of activity coefficients for aqueous organic redox flow batteries: Theoretical basis and equations
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Gaël Mourouga, Déborah Chery, Emmanuel Baudrin, Hyacinthe Randriamahazaka, Thomas J. Schmidt, and Juergen O. Schumacher
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Chemistry ,Electrochemistry ,Electrochemical energy storage ,Computational chemistry ,Science - Abstract
Summary: The field of aqueous organic redox flow batteries (AORFBs) has been developing fast in recent years, and many chemistries are starting to emerge as serious contenders for grid-scale storage. The industrial development of these systems would greatly benefit from accurate physics-based models, allowing to optimize battery operation and design. Many authors in the field of flow battery modeling have brought evidence that the dilute solution hypothesis (the assumption that aqueous electrolytes behave ideally) does not hold for these systems and that calculating cell voltage or chemical potentials through concentrations rather than activities, while serviceable, may become insufficient when greater accuracy is required. This article aims to provide the theoretical basis for calculating activity coefficients of aqueous organic electrolytes used in AORFBs to provide tools to predict the concentrated behavior of aqueous electrolytes, thereby improving the accuracy of physics-based models for flow batteries.
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- 2022
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20. Follicular Delivery of Caffeine from a Shampoo for Hair Retention
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Loris Busch, Anna Lena Klein, James R. Schwartz, Kathleen Pearson, Heike Richter, Sabine Schanzer, Silke B. Lohan, Fabian Schumacher, Burkhard Kleuser, and Martina C. Meinke
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hair loss ,caffeine ,shampoo ,hair follicles ,Chemistry ,QD1-999 - Abstract
A key factor in the prevention of hair loss is the provision of optimal conditions on the scalp. In this regard, reduction of oxidative stress on the scalp is one critical requirement to support the hair follicles to function optimally. Recently, a novel shampoo formulation technology containing anti-oxidants such as piroctone olamine has been demonstrated to improve hair retention based on micellar degradation and coacervation effects. Caffeine has also been shown to exhibit anti-oxidant activity including the ability to inhibit lipid peroxidation. As with piroctone olamine, it is expected that follicular delivery of caffeine will enhance its anti-oxidant activity in a region that will be beneficial for hair retention. In this study, two shampoo formulations as well as a control formulation were applied to the calf area of n = 9 male participants. The technique of differential tape stripping was applied to obtain the caffeine penetrated to the stratum corneum and to the hair follicles. Isotope-dilution liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was performed to demonstrate caffeine follicular delivery from the shampoo formulas. The results showed that the percentage of caffeine recovered in the hair follicles was 8–9% of the caffeine absorbed into the skin and matched an existing caffeine-based shampoo. In conclusion, a novel shampoo formulation technology has been developed that effectively delivers beneficial anti-oxidants to improve hair retention. This new shampoo is expected to be especially useful in the goal of retaining hair during aging.
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- 2023
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21. Lighting Up the Organochalcogen Synthesis: A Concise Update of Recent Photocatalyzed Approaches
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Ricardo H. Bartz, Luiz H. Dapper, Jean C. Kazmierczak, Ricardo F. Schumacher, Gelson Perin, Samuel Thurow, Filipe Penteado, and Eder J. Lenardão
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photocatalysis ,visible light ,green chemistry ,organochalcogen ,organosulfur ,organoselenium ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
This review describes the recent advances in photocatalyzed reactions to form new carbon–sulfur and carbon–selenium bonds. With a total of 136 references, of which 81 articles are presented, the authors introduce in five sections an updated picture of the state of the art in the light-promoted synthesis of organochalcogen compounds (from 2019 to present). The light-promoted synthesis of sulfides by direct sulfenylation of C–C π-bonds; synthesis of sulfones; the activation of Csp2–N bond in the formation of Csp2–S bonds; synthesis of thiol ester, thioether and thioacetal; and the synthesis of organoselenium compounds are discussed, with detailed reaction conditions and selected examples for each protocol.
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- 2023
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22. Synthesis of enantiomerically pure glycerol derivatives containing an organochalcogen unit: In vitro and in vivo antioxidant activity
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Patrick C. Nobre, Henrique A. Vargas, Caroline G. Jacoby, Paulo H. Schneider, Angela M. Casaril, Lucielli Savegnago, Ricardo F. Schumacher, Eder J. Lenardão, Daiana S. Ávila, Luiz B.L. Rodrigues Junior, and Gelson Perin
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Chemistry ,QD1-999 - Abstract
We describe here the synthesis of enantiomerically pure chalcogenoethers obtained through the reaction of nucleophilic species of chalcogen (S, Se and Te), generated in situ from the respective diorganyl dichalcogenides, with (R)- and (S)-tosyl solketal. Furthermore, some of the chalcogenoethers were treated with acidic cation exchange resin Dowex-(H+) leading to the respective deprotected enantiomerically pure 3-phenylchalcogenyl-1,2-diols. In order to explore the biological potential of these molecules, the antioxidant activity of some organochalcogens was evaluated by several in vitro assays. Overall, the chalcogenoethers containing Te were better scavengers of DPPH and ABTS·+ radicals, had higher ferric reducing capacity and prevented lipid peroxidation. To analyze the effects of these compounds in vivo, we used the alternative model Caenorhabditis elegans. Chalcogenoethers treatment, especially (S)- and (R)-2,2-dimethyl-4-(phenylselanylmethyl)-1,3-dioxolane, conferred protection against the mortality-induced by hydrogen peroxide. Accordingly, these chalcogenoethers were able to modulate the antioxidant enzyme catalase. Notably, the compounds did not present toxicity in worm’s reproduction. To sum up, our study demonstrated that Te- containing chalcogenoethers were promising in vitro scavengers, while Se molecules were more prone to protect against a stressor in vivo. In this sense, the antioxidant activity of chalcogenoethers, especially with Se and Te, indicates that these molecules may have biological application in an attempt to reduce the oxidative stress. Keywords: Organochalcogen, Chiral, Chalcogenoethers, PEG-400, Antioxidant, Caenorhabditis elegans
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- 2020
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23. Salinity-Induced Cytosolic Alkaline Shifts in Arabidopsis Roots Require the SOS Pathway
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Belén Rombolá-Caldentey, Zaida Andrés, Rainer Waadt, Francisco J. Quintero, Karin Schumacher, and José M. Pardo
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salinity ,cytosolic pH ,salt-related signaling ,SOS3/CBL4 ,roots ,Arabidopsis ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Plants have evolved elaborate mechanisms to sense, respond to and overcome the detrimental effects of high soil salinity. The role of calcium transients in salinity stress signaling is well established, but the physiological significance of concurrent salinity-induced changes in cytosolic pH remains largely undefined. Here, we analyzed the response of Arabidopsis roots expressing the genetically encoded ratiometric pH-sensor pHGFP fused to marker proteins for the recruitment of the sensor to the cytosolic side of the tonoplast (pHGFP-VTI11) and the plasma membrane (pHGFP-LTI6b). Salinity elicited a rapid alkalinization of cytosolic pH (pHcyt) in the meristematic and elongation zone of wild-type roots. The pH-shift near the plasma membrane preceded that at the tonoplast. In pH-maps transversal to the root axis, the epidermis and cortex had cells with a more alkaline pHcyt relative to cells in the stele in control conditions. Conversely, seedlings treated with 100 mM NaCl exhibited an increased pHcyt in cells of the vasculature relative to the external layers of the root, and this response occurred in both reporter lines. These pHcyt changes were substantially reduced in mutant roots lacking a functional SOS3/CBL4 protein, suggesting that the operation of the SOS pathway mediated the dynamics of pHcyt in response to salinity.
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- 2023
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24. Perinatal Obesity Sensitizes for Premature Kidney Aging Signaling
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Jaco Selle, Katrin Bohl, Katja Höpker, Rebecca Wilke, Katharina Dinger, Philipp Kasper, Bastian Abend, Bernhard Schermer, Roman-Ulrich Müller, Christine Kurschat, Kai-Dietrich Nüsken, Eva Nüsken, David Meyer, Soni Savai Pullamsetti, Björn Schumacher, Jörg Dötsch, and Miguel A. Alejandre Alcazar
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chronic kidney disease ,perinatal obesity ,DNA damage response ,kidney aging ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Chronic Kidney Disease (CKD), a global health burden, is strongly associated with age-related renal function decline, hypertension, and diabetes, which are all frequent consequences of obesity. Despite extensive studies, the mechanisms determining susceptibility to CKD remain insufficiently understood. Clinical evidence together with prior studies from our group showed that perinatal metabolic disorders after intrauterine growth restriction or maternal obesity adversely affect kidney structure and function throughout life. Since obesity and aging processes converge in similar pathways we tested if perinatal obesity caused by high-fat diet (HFD)-fed dams sensitizes aging-associated mechanisms in kidneys of newborn mice. The results showed a marked increase of γH2AX-positive cells with elevated 8-Oxo-dG (RNA/DNA damage), both indicative of DNA damage response and oxidative stress. Using unbiased comprehensive transcriptomics we identified compartment-specific differentially-regulated signaling pathways in kidneys after perinatal obesity. Comparison of these data to transcriptomic data of naturally aged kidneys and prematurely aged kidneys of genetic modified mice with a hypomorphic allele of Ercc1, revealed similar signatures, e.g., inflammatory signaling. In a biochemical approach we validated pathways of inflammaging in the kidneys after perinatal obesity. Collectively, our initial findings demonstrate premature aging-associated processes as a consequence of perinatal obesity that could determine the susceptibility for CKD early in life.
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- 2023
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25. Sphingosine as a New Antifungal Agent against Candida and Aspergillus spp.
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Fahimeh Hashemi Arani, Stephanie Kadow, Melanie Kramer, Simone Keitsch, Lisa Kirchhoff, Fabian Schumacher, Burkhard Kleuser, Peter-Michael Rath, Erich Gulbins, and Alexander Carpinteiro
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sphingosine ,sphingolipids ,mitochondria ,pulmonary aspergillosis ,aspergillus ,candida ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
This study investigated whether sphingosine is effective as prophylaxis against Aspergillus spp. and Candida spp. In vitro experiments showed that sphingosine is very efficacious against A. fumigatus and Nakeomyces glabrataa (formerly named C. glabrata). A mouse model of invasive aspergillosis showed that sphingosine exerts a prophylactic effect and that sphingosine-treated animals exhibit a strong survival advantage after infection. Furthermore, mechanistic studies showed that treatment with sphingosine leads to the early depolarization of the mitochondrial membrane potential (Δψm) and the generation of mitochondrial reactive oxygen species and to a release of cytochrome C within minutes, thereby presumably initiating apoptosis. Because of its very good tolerability and ease of application, inhaled sphingosine should be further developed as a possible prophylactic agent against pulmonary aspergillosis among severely immunocompromised patients.
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- 2022
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26. Endogenous Modulation of Extracellular Matrix Collagen during Scar Formation after Myocardial Infarction
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David Schumacher, Adelina Curaj, Mareike Staudt, Sakine Simsekyilmaz, Isabella Kanzler, Peter Boor, Barbara Mara Klinkhammer, Xiaofeng Li, Octavian Bucur, Adnan Kaabi, Yichen Xu, Huabo Zheng, Pakhwan Nilcham, Alexander Schuh, Mihaela Rusu, and Elisa A. Liehn
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myocardial infarction ,scar formation ,extracellular matrix ,remodeling ,inflammation ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Myocardial infarction is remains the leading cause of death in developed countries. Recent data show that the composition of the extracellular matrix might differ despite similar heart function and infarction sizes. Because collagen is the main component of the extracellular matrix, we hypothesized that changes in inflammatory cell recruitment influence the synthesis of different collagen subtypes in myofibroblasts, thus changing the composition of the scar. We found that neutrophils sustain the proliferation of fibroblasts, remodeling, differentiation, migration and inflammation, predominantly by IL-1 and PPARγ pathways (n = 3). They also significantly inhibit the mRNA expression of fibrillar collagen, maintaining a reduced stiffness in isolated myofibroblasts (n = 4–5). Reducing the neutrophil infiltration in CCR1−/− resulted in increased mRNA expression of collagen 11, moderate expression of collagen 19 and low expression of collagen 13 and 26 in the scar 4 weeks post infarction compared with other groups (n = 3). Mononuclear cells increased the synthesis of all collagen subtypes and upregulated the NF-kB, angiotensin II and PPARδ pathways (n = 3). They increased the synthesis of collagen subtypes 1, 3, 5, 16 and 23 but reduced the expression of collagens 5 and 16 (n = 3). CCR2−/− scar tissue showed higher levels of collagen 13 (n = 3), in association with a significant reduction in stiffness (n = 4–5). Upregulation of the inflammation-related genes in myofibroblasts mostly modulated the fibrillar collagen subtypes, with less effect on the FACIT, network-forming and globular subtypes (n = 3). The upregulation of proliferation and differentiation genes in myofibroblasts seemed to be associated only with the fibrillar collagen subtype, whereas angiogenesis-related genes are associated with fibrillar, network-forming and multiplexin subtypes. In conclusion, although we intend for our findings to deepen the understanding of the mechanism of healing after myocardial infarction and scar formation, the process of collagen synthesis is highly complex, and further intensive investigation is needed to put together all the missing puzzle pieces in this still incipient knowledge process.
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- 2022
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27. Antiviral and Anti-Inflammatory Activities of Fluoxetine in a SARS-CoV-2 Infection Mouse Model
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David Péricat, Stephen Adonai Leon-Icaza, Marina Sanchez Rico, Christiane Mühle, Iulia Zoicas, Fabian Schumacher, Rémi Planès, Raoul Mazars, Germain Gros, Alexander Carpinteiro, Katrin Anne Becker, Jacques Izopet, Nathalie Strub-Wourgaft, Peter Sjö, Olivier Neyrolles, Burkhard Kleuser, Frédéric Limosin, Erich Gulbins, Johannes Kornhuber, Etienne Meunier, Nicolas Hoertel, and Céline Cougoule
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COVID-19 ,SARS-CoV-2 ,mouse model ,fluoxetine ,anti-depressant ,inflammation ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The coronavirus disease 2019 (COVID-19) pandemic continues to cause significant morbidity and mortality worldwide. Since a large portion of the world’s population is currently unvaccinated or incompletely vaccinated and has limited access to approved treatments against COVID-19, there is an urgent need to continue research on treatment options, especially those at low cost and which are immediately available to patients, particularly in low- and middle-income countries. Prior in vitro and observational studies have shown that fluoxetine, possibly through its inhibitory effect on the acid sphingomyelinase/ceramide system, could be a promising antiviral and anti-inflammatory treatment against COVID-19. In this report, we evaluated the potential antiviral and anti-inflammatory activities of fluoxetine in a K18-hACE2 mouse model of SARS-CoV-2 infection, and against variants of concern in vitro, i.e., SARS-CoV-2 ancestral strain, Alpha B.1.1.7, Gamma P1, Delta B1.617 and Omicron BA.5. Fluoxetine, administrated after SARS-CoV-2 infection, significantly reduced lung tissue viral titres and expression of several inflammatory markers (i.e., IL-6, TNFα, CCL2 and CXCL10). It also inhibited the replication of all variants of concern in vitro. A modulation of the ceramide system in the lung tissues, as reflected by the increase in the ratio HexCer 16:0/Cer 16:0 in fluoxetine-treated mice, may contribute to explain these effects. Our findings demonstrate the antiviral and anti-inflammatory properties of fluoxetine in a K18-hACE2 mouse model of SARS-CoV-2 infection, and its in vitro antiviral activity against variants of concern, establishing fluoxetine as a very promising candidate for the prevention and treatment of SARS-CoV-2 infection and disease pathogenesis.
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- 2022
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28. Zn-Loaded and Calcium Phosphate-Coated Degradable Silica Nanoparticles Can Effectively Promote Osteogenesis in Human Mesenchymal Stem Cells
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Pichaporn Sutthavas, Matthias Schumacher, Kai Zheng, Pamela Habibović, Aldo Roberto Boccaccini, and Sabine van Rijt
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silica nanoparticles ,bioactive glass ,bone regeneration ,zinc ,inorganic ion doping ,ceramics ,Chemistry ,QD1-999 - Abstract
Nanoparticles such as mesoporous bioactive glasses (MBGs) and mesoporous silica nanoparticles (MSN) are promising for use in bone regeneration applications due to their inherent bioactivity. Doping silica nanoparticles with bioinorganic ions could further enhance their biological performance. For example, zinc (Zn) is often used as an additive because it plays an important role in bone formation and development. Local delivery and dose control are important aspects of its therapeutic application. In this work, we investigated how Zn incorporation in MSN and MBG nanoparticles impacts their ability to promote human mesenchymal stem cell (hMSC) osteogenesis and mineralization in vitro. Zn ions were incorporated in three different ways; within the matrix, on the surface or in the mesopores. The nanoparticles were further coated with a calcium phosphate (CaP) layer to allow pH-responsive delivery of the ions. We demonstrate that the Zn incorporation amount and ion release profile affect the nanoparticle’s ability to stimulate osteogenesis in hMSCs. Specifically, we show that the nanoparticles that contain rapid Zn release profiles and a degradable silica matrix were most effective in inducing hMSC differentiation. Moreover, cells cultured in the presence of nanoparticle-containing media resulted in the highest induction of alkaline phosphate (ALP) activity, followed by culturing hMSC on nanoparticles immobilized on the surface as films. Exposure to nanoparticle-conditioned media did not increase ALP activity in hMSCs. In summary, Zn incorporation mode and nanoparticle application play an important role in determining the bioactivity of ion-doped silica nanoparticles.
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- 2022
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29. Perinatal Obesity Induces Hepatic Growth Restriction with Increased DNA Damage Response, Senescence, and Dysregulated Igf-1-Akt-Foxo1 Signaling in Male Offspring of Obese Mice
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Philipp Kasper, Jaco Selle, Christina Vohlen, Rebecca Wilke, Celien Kuiper-Makris, Oleksiy Klymenko, Inga Bae-Gartz, Charlotte Schömig, Alexander Quaas, Björn Schumacher, Münevver Demir, Martin Bürger, Sonja Lang, Anna Martin, Hans-Michael Steffen, Tobias Goeser, Jörg Dötsch, and Miguel A. Alejandre Alcazar
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metabolic programming ,liver ,maternal obesity ,cellular senescence ,aging ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Maternal obesity predisposes for hepato-metabolic disorders early in life. However, the underlying mechanisms causing early onset dysfunction of the liver and metabolism remain elusive. Since obesity is associated with subacute chronic inflammation and accelerated aging, we test the hypothesis whether maternal obesity induces aging processes in the developing liver and determines thereby hepatic growth. To this end, maternal obesity was induced with high-fat diet (HFD) in C57BL/6N mice and male offspring were studied at the end of the lactation [postnatal day 21 (P21)]. Maternal obesity induced an obese body composition with metabolic inflammation and a marked hepatic growth restriction in the male offspring at P21. Proteomic and molecular analyses revealed three interrelated mechanisms that might account for the impaired hepatic growth pattern, indicating prematurely induced aging processes: (1) Increased DNA damage response (γH2AX), (2) significant upregulation of hepatocellular senescence markers (Cdnk1a, Cdkn2a); and (3) inhibition of hepatic insulin/insulin-like growth factor (IGF)-1-AKT-p38-FoxO1 signaling with an insufficient proliferative growth response. In conclusion, our murine data demonstrate that perinatal obesity induces an obese body composition in male offspring with hepatic growth restriction through a possible premature hepatic aging that is indicated by a pathologic sequence of inflammation, DNA damage, senescence, and signs of a possibly insufficient regenerative capacity.
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- 2022
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30. A Co-Polymerizable Linker for the Covalent Attachment of Fibronectin Makes pHEMA Hydrogels Cell-Adhesive
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Laura Schumacher, Katharina Siemsen, Clement Appiah, Sunil Rajput, Anne Heitmann, Christine Selhuber-Unkel, and Anne Staubitz
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polymer ,pHEMA ,bio-conjugation ,hydrogel ,biocompatibility ,Science ,Chemistry ,QD1-999 ,Inorganic chemistry ,QD146-197 ,General. Including alchemy ,QD1-65 - Abstract
Hydrogels are attractive biomaterials because their chemical and mechanical properties can be tailored to mimic those of biological tissues. However, many hydrogels do not allow cell or protein attachment. Therefore, they are post-synthetically functionalized by adding functional groups for protein binding, which then allows cell adhesion in cell culture substrates. However, the degree of functionalization and covalent binding is difficult to analyze in these cases. Moreover, the density of the functional groups and the homogeneity of their distribution is hard to control. This work introduces another strategy for the biofunctionalization of hydrogels: we synthesized a polymerizable linker that serves as a direct junction between the polymeric structure and cell adhesion proteins. This maleimide-containing, polymerizable bio-linker was copolymerized with non-functionalized monomers to produce a bioactive hydrogel based on poly(2-hydroxyethyl methacrylate) (pHEMA). Therefore, the attachment site was only controlled by the polymerization process and was thus uniformly distributed throughout the hydrogel. In this way, the bio-conjugation by a protein-binding thiol-maleimide Michael-type reaction was possible in the entire hydrogel matrix. This approach enabled a straightforward and highly effective biofunctionalization of pHEMA with the adhesion protein fibronectin. The bioactivity of the materials was demonstrated by the successful adhesion of fibroblast cells.
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- 2022
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31. Impact of Nano- and Micro-Sized Chromium(III) Particles on Cytotoxicity and Gene Expression Profiles Related to Genomic Stability in Human Keratinocytes and Alveolar Epithelial Cells
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Paul Schumacher, Franziska Fischer, Joachim Sann, Dirk Walter, and Andrea Hartwig
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Cr2O3 particles ,Cr(VI) release ,cytotoxicity ,gene expression profiles ,DNA damage signaling ,DNA repair proteins ,Chemistry ,QD1-999 - Abstract
Exposure to Cr(VI) compounds has been consistently associated with genotoxicity and carcinogenicity, whereas Cr(III) is far less toxic, due to its poor cellular uptake. However, contradictory results have been published in relation to particulate Cr2O3. The aim of the present study was to investigate whether Cr(III) particles exerted properties comparable to water soluble Cr(III) or to Cr(VI), including two nano-sized and one micro-sized particles. The morphology and size distribution were determined by TEM, while the oxidation state was analyzed by XPS. Chromium release was quantified via AAS, and colorimetrically differentiated between Cr(VI) and Cr(III). Furthermore, the toxicological fingerprints of the Cr2O3 particles were established using high-throughput RT-qPCR and then compared to water-soluble Cr(VI) and Cr(III) in A549 and HaCaT cells. Regarding the Cr2O3 particles, two out of three exerted only minor or no toxicity, and the gene expression profiles were comparable to Cr(III). However, one particle under investigation released considerable amounts of Cr(VI), and also resembled the toxicity profiles of Cr(VI); this was also evident in the altered gene expression related to DNA damage signaling, oxidative stress response, inflammation, and cell death pathways. Even though the highest toxicity was found in the case of the smallest particle, size did not appear to be the decisive parameter, but rather the purity of the Cr(III) particles with respect to Cr(VI) content.
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- 2022
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32. Cyclizing Painkillers: Development of Backbone-Cyclic TAPS Analogs
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Alaa Talhami, Avi Swed, Shmuel Hess, Oded Ovadia, Sarit Greenberg, Adi Schumacher-Klinger, David Rosenthal, Deborah E. Shalev, Mattan Hurevich, Philip Lazarovici, Amnon Hoffman, and Chaim Gilon
- Subjects
reductive alkylation ,backbone cyclization ,cycloscan ,TAPS ,peripheral painkiller ,Chemistry ,QD1-999 - Abstract
Painkillers are commonly used medications. Native peptide painkillers suffer from various pharmacological disadvantages, while small molecule painkillers like morphine are highly addictive. We present a general approach aimed to use backbone-cyclization to develop a peptidomimetic painkiller. Backbone-cyclization was applied to transform the linear peptide Tyr-Arg-Phe-Sar (TAPS) into an active backbone-cyclic peptide with improved drug properties. We designed and synthesized a focused backbone-cyclic TAPS library with conformational diversity, in which the members of the library have the generic name TAPS c(n-m) where n and m represent the lengths of the alkyl chains on the nitrogens of Gly and Arg, respectively. We used a combined screening approach to evaluate the pharmacological properties and the potency of the TAPS c(n-m) library. We focused on an in vivo active compound, TAPS c(2-6), which is metabolically stable and has the potential to become a peripheral painkiller being a full μ opioid receptor functional agonist. To prepare a large quantity of TAPS c(2-6), we optimized the conditions of the on-resin reductive alkylation step to increase the efficiency of its SPPS. NMR was used to determine the solution conformation of the peptide lead TAPS c(2-6).
- Published
- 2020
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33. Cloud characteristics, thermodynamic controls and radiative impacts during the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) experiment
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S. E. Giangrande, Z. Feng, M. P. Jensen, J. M. Comstock, K. L. Johnson, T. Toto, M. Wang, C. Burleyson, N. Bharadwaj, F. Mei, L. A. T. Machado, A. O. Manzi, S. Xie, S. Tang, M. A. F. Silva Dias, R. A. F. de Souza, C. Schumacher, and S. T. Martin
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Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Routine cloud, precipitation and thermodynamic observations collected by the Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) and Aerial Facility (AAF) during the 2-year US Department of Energy (DOE) ARM Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) campaign are summarized. These observations quantify the diurnal to large-scale thermodynamic regime controls on the clouds and precipitation over the undersampled, climatically important Amazon basin region. The extended ground deployment of cloud-profiling instrumentation enabled a unique look at multiple cloud regimes at high temporal and vertical resolution. This longer-term ground deployment, coupled with two short-term aircraft intensive observing periods, allowed new opportunities to better characterize cloud and thermodynamic observational constraints as well as cloud radiative impacts for modeling efforts within typical Amazon wet and dry seasons.
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- 2017
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34. Apolipoprotein E4 Is Associated with Right Ventricular Dysfunction in Dilated Cardiomyopathy—An Animal and In-Human Comparative Study
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Rodica Diaconu, Nicole Schaaps, Mamdouh Afify, Peter Boor, Anne Cornelissen, Roberta A. Florescu, Sakine Simsekyilmaz, Teddy El-Khoury, David Schumacher, Mihai Ioana, Ioana Streata, Constantin Militaru, Ionut Donoiu, Felix Vogt, and Elisa A. Liehn
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apoE ,cardiovascular models ,dilated cardiomyopathy ,right ventricular systolic dysfunction ,ε4 allele ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
ApoE abnormality represents a well-known risk factor for cardiovascular diseases. Beyond its role in lipid metabolism, novel studies demonstrate a complex involvement of apoE in membrane homeostasis and signaling as well as in nuclear transcription. Due to the large spread of apoE isoforms in the human population, there is a need to understand the apoE’s role in pathological processes. Our study aims to dissect the involvement of apoE in heart failure. We showed that apoE-deficient rats present multiple organ damages (kidney, liver, lung and spleen) besides the known predisposition for obesity and affected lipid metabolism (two-fold increase in tissular damages in liver and one-fold increase in kidney, lung and spleen). Heart tissue also showed significant morphological changes in apoE−/− rats, mostly after a high-fat diet. Interestingly, the right ventricle of apoE−/− rats fed a high-fat diet showed more damage and affected collagen content (~60% less total collagen content and double increase in collagen1/collagen3 ratio) compared with the left ventricle (no significant differences in total collagen content or collagen1/collagen3 ratio). In patients, we were able to find a correlation between the presence of ε4 allele and cardiomyopathy (χ2 = 10.244; p = 0.001), but also with right ventricle dysfunction with decreased TAPSE (15.3 ± 2.63 mm in ε4-allele-presenting patients vs. 19.8 ± 3.58 mm if the ε4 allele is absent, p < 0.0001*) and increased in systolic pulmonary artery pressure (50.44 ± 16.47 mmHg in ε4-allele-presenting patients vs. 40.68 ± 15.94 mmHg if the ε4 allele is absent, p = 0.0019). Our results confirm that the presence of the ε4 allele is a lipid-metabolism-independent risk factor for heart failure. Moreover, we show for the first time that the presence of the ε4 allele is associated with right ventricle dysfunction, implying different regulatory mechanisms of fibroblasts and the extracellular matrix in both ventricles. This is essential to be considered and thoroughly investigated before the design of therapeutical strategies for patients with heart failure.
- Published
- 2021
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35. Mouse Liver Compensates Loss of Sgpl1 by Secretion of Sphingolipids into Blood and Bile
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Anna Katharina Spohner, Katja Jakobi, Sandra Trautmann, Dominique Thomas, Fabian Schumacher, Burkhard Kleuser, Dieter Lütjohann, Khadija El-Hindi, Sabine Grösch, Josef Pfeilschifter, Julie D. Saba, and Dagmar Meyer zu Heringdorf
- Subjects
sphingosine-1-phosphate ,SGPL1 ,ceramides ,cholesterol ,liver ,bile ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Sphingosine 1 phosphate (S1P) lyase (Sgpl1) catalyses the irreversible cleavage of S1P and thereby the last step of sphingolipid degradation. Loss of Sgpl1 in humans and mice leads to accumulation of sphingolipids and multiple organ injuries. Here, we addressed the role of hepatocyte Sgpl1 for regulation of sphingolipid homoeostasis by generating mice with hepatocyte-specific deletion of Sgpl1 (Sgpl1HepKO mice). Sgpl1HepKO mice had normal body weight, liver weight, liver structure and liver enzymes both at the age of 8 weeks and 8 months. S1P, sphingosine and ceramides, but not glucosylceramides or sphingomyelin, were elevated by ~1.5–2-fold in liver, and this phenotype did not progress with age. Several ceramides were elevated in plasma, while plasma S1P was normal. Interestingly, S1P and glucosylceramides, but not ceramides, were elevated in bile of Sgpl1HepKO mice. Furthermore, liver cholesterol was elevated, while LDL cholesterol decreased in 8-month-old mice. In agreement, the LDL receptor was upregulated, suggesting enhanced uptake of LDL cholesterol. Expression of peroxisome proliferator-activated receptor-γ, liver X receptor and fatty acid synthase was unaltered. These data show that mouse hepatocytes largely compensate the loss of Sgpl1 by secretion of accumulating sphingolipids in a specific manner into blood and bile, so that they can be excreted or degraded elsewhere.
- Published
- 2021
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36. Nitro-Oleic Acid (NO2-OA) Improves Systolic Function in Dilated Cardiomyopathy by Attenuating Myocardial Fibrosis
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Simon Braumann, Wibke Schumacher, Nam Gyu Im, Felix Sebastian Nettersheim, Dennis Mehrkens, Senai Bokredenghel, Alexander Hof, Richard Julius Nies, Christoph Adler, Holger Winkels, Ralph Knöll, Bruce A. Freeman, Volker Rudolph, Anna Klinke, Matti Adam, Stephan Baldus, Martin Mollenhauer, and Simon Geißen
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nitro-oleic acid ,dilated cardiomyopathy ,muscle LIM protein ,myocardial fibrosis ,TGFβ ,alpha smooth muscle actin ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Nitro-oleic acid (NO2-OA), a nitric oxide (NO)- and nitrite (NO2−)-derived electrophilic fatty acid metabolite, displays anti-inflammatory and anti-fibrotic signaling actions and therapeutic benefit in murine models of ischemia-reperfusion, atrial fibrillation, and pulmonary hypertension. Muscle LIM protein-deficient mice (Mlp−/−) develop dilated cardiomyopathy (DCM), characterized by impaired left ventricular function and increased ventricular fibrosis at the age of 8 weeks. This study investigated the effects of NO2-OA on cardiac function in Mlp−/− mice both in vivo and in vitro. Mlp−/− mice were treated with NO2-OA or vehicle for 4 weeks via subcutaneous osmotic minipumps. Wildtype (WT) littermates treated with vehicle served as controls. Mlp−/− mice exhibited enhanced TGFβ signalling, fibrosis and severely reduced left ventricular systolic function. NO2-OA treatment attenuated interstitial myocardial fibrosis and substantially improved left ventricular systolic function in Mlp−/− mice. In vitro studies of TGFβ-stimulated primary cardiac fibroblasts further revealed that the anti-fibrotic effects of NO2-OA rely on its capability to attenuate fibroblast to myofibroblast transdifferentiation by inhibiting phosphorylation of TGFβ downstream targets. In conclusion, we demonstrate a substantial therapeutic benefit of NO2-OA in a murine model of DCM, mediated by interfering with endogenously activated TGFβ signaling.
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- 2021
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37. A Ti/Pt/Co Multilayer Stack for Transfer Function Based Magnetic Force Microscopy Calibrations
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Baha Sakar, Sibylle Sievers, Alexander Fernández Scarioni, Felipe Garcia-Sanchez, İlker Öztoprak, Hans Werner Schumacher, and Osman Öztürk
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magnetic force microscopy ,calibration ,reference samples ,micromagnetism ,metrology for magnetism ,magnetic multilayers ,Chemistry ,QD1-999 - Abstract
Magnetic force microscopy (MFM) is a widespread technique for imaging magnetic structures with a resolution of some 10 nanometers. MFM can be calibrated to obtain quantitative (qMFM) spatially resolved magnetization data in units of A/m by determining the calibrated point spread function of the instrument, its instrument calibration function (ICF), from a measurement of a well-known reference sample. Beyond quantifying the MFM data, a deconvolution of the MFM image data with the ICF also corrects the smearing caused by the finite width of the MFM tip stray field distribution. However, the quality of the calibration depends critically on the calculability of the magnetization distribution of the reference sample. Here, we discuss a Ti/Pt/Co multilayer stack that shows a stripe domain pattern as a suitable reference material. A precise control of the fabrication process, combined with a characterization of the sample micromagnetic parameters, allows reliable calculation of the sample’s magnetic stray field, proven by a very good agreement between micromagnetic simulations and qMFM measurements. A calibrated qMFM measurement using the Ti/Pt/Co stack as a reference sample is shown and validated, and the application area for quantitative MFM measurements calibrated with the Ti/Pt/Co stack is discussed.
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- 2021
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38. Genome-Wide Approach to Identify Quantitative Trait Loci for Drought Tolerance in Tetraploid Potato (Solanum tuberosum L.)
- Author
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Christina Schumacher, Susanne Thümecke, Florian Schilling, Karin Köhl, Joachim Kopka, Heike Sprenger, Dirk Karl Hincha, Dirk Walther, Sylvia Seddig, Rolf Peters, Ellen Zuther, Manuela Haas, and Renate Horn
- Subjects
drought tolerance ,ethylene ,brassinosteroids ,cell wall ,tuber starch content ,tuber starch yield ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Drought represents a major abiotic stress factor negatively affecting growth, yield and tuber quality of potatoes. Quantitative trait locus (QTL) analyses were performed in cultivated potatoes for drought tolerance index DRYM (deviation of relative starch yield from the experimental median), tuber starch content, tuber starch yield, tuber fresh weight, selected transcripts and metabolites under control and drought stress conditions. Eight genomic regions of major interest for drought tolerance were identified, three representing standalone DRYM QTL. Candidate genes, e.g., from signaling pathways for ethylene, abscisic acid and brassinosteroids, and genes encoding cell wall remodeling enzymes were identified within DRYM QTL. Co-localizations of DRYM QTL and QTL for tuber starch content, tuber starch yield and tuber fresh weight with underlying genes of the carbohydrate metabolism were observed. Overlaps of DRYM QTL with metabolite QTL for ribitol or galactinol may indicate trade-offs between starch and compatible solute biosynthesis. Expression QTL confirmed the drought stress relevance of selected transcripts by overlaps with DRYM QTL. Bulked segregant analyses combined with next-generation sequencing (BSAseq) were used to identify mutations in genes under the DRYM QTL on linkage group 3. Future analyses of identified genes for drought tolerance will give a better insight into drought tolerance in potatoes.
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- 2021
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39. Quantification of Mineral Oil Aromatic Hydrocarbons (MOAH) in Anhydrous Cosmetics Using 1H NMR
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Sandra Weber, Tamina Schmidt, Paul Schumacher, Thomas Kuballa, Gerd Mildau, Stephan G. Walch, Andrea Hartwig, and Dirk W. Lachenmeier
- Subjects
Chemistry ,QD1-999 - Abstract
In cosmetic products, hydrocarbons from mineral oil origin are used as ingredients in a wide variety of consistency, from liquid oil to solid wax. Refined mineral oil hydrocarbons consist of MOSH (mineral oil saturated hydrocarbons) and a low proportion of MOAH (mineral oil aromatic hydrocarbons). MOSH and MOAH comprise a variety of chemically similar single substances with straight or branched chains. In the context of precautionary consumer protection, it is crucial to determine hydrocarbons from mineral oil origin of inferior quality quickly and efficiently. This publication presents a rapid method for quantifying MOAH by proton nuclear magnetic resonance spectroscopy (1H qNMR) in anhydrous cosmetics such as lipstick, lip gloss, and lip balm. A sample clean-up using solid-phase extraction (SPE) was developed for the complete removal of interfering aromatic substances to improve the robustness of the method for analysing compounded cosmetics. In preliminary trials using silica gel thin-layer chromatography, the retention behaviour of 21 common aromatic compounds was tested in eluents with different solvent strength including EtOAc, MeOH, cyclohexane, and dichloromethane. Based on these results, the SPE sample cleanup with silica gel and cyclohexane as an eluent was suggested as best suitable for the purpose. The SPE cleanup was successfully achieved for all tested potentially interfering aromatic cosmetic ingredients except for butylated hydroxytoluene. The recovery for lipophilic cosmetics is more than 80% based on naphthalene as calculation equivalent. Furthermore, a specific sample preparation for the examination of lipsticks was implemented. The SPE cleanup was validated, and the robustness of the method was tested on 57 samples from the retail trade. The 1H qNMR method is a good complement to the LC-GC-FID method, which is predominantly used for the determination of MOSH and MOAH. Chromatographic problems such as migration of MOSH into the MOAH fraction during LC-GC-FID can be avoided.
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- 2019
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40. Epigenetic DNA Methylation of EBI3 Modulates Human Interleukin-35 Formation via NFkB Signaling: A Promising Therapeutic Option in Ulcerative Colitis
- Author
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Alexandra Wetzel, Bettina Scholtka, Fabian Schumacher, Harshadrai Rawel, Birte Geisendörfer, and Burkhard Kleuser
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decitabine ,DNMT inhibitor ,EBI3 ,inhibitory cytokines ,interleukin-35 ,TNFα ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Ulcerative colitis (UC), a severe chronic disease with unclear etiology that is associated with increased risk for colorectal cancer, is accompanied by dysregulation of cytokines. Epstein–Barr virus-induced gene 3 (EBI3) encodes a subunit in the unique heterodimeric IL-12 cytokine family of either pro- or anti-inflammatory function. After having recently demonstrated that upregulation of EBI3 by histone acetylation alleviates disease symptoms in a dextran sulfate sodium (DSS)-treated mouse model of chronic colitis, we now aimed to examine a possible further epigenetic regulation of EBI3 by DNA methylation under inflammatory conditions. Treatment with the DNA methyltransferase inhibitor (DNMTi) decitabine (DAC) and TNFα led to synergistic upregulation of EBI3 in human colon epithelial cells (HCEC). Use of different signaling pathway inhibitors indicated NFκB signaling was necessary and proportional to the synergistic EBI3 induction. MALDI-TOF/MS and HPLC-ESI-MS/MS analysis of DAC/TNFα-treated HCEC identified IL-12p35 as the most probable binding partner to form a functional protein. EBI3/IL-12p35 heterodimers (IL-35) induce their own gene upregulation, something that was indeed observed in HCEC cultured with media from previously DAC/TNFα-treated HCEC. These results suggest that under inflammatory and demethylating conditions the upregulation of EBI3 results in the formation of anti-inflammatory IL-35, which might be considered as a therapeutic target in colitis.
- Published
- 2021
- Full Text
- View/download PDF
41. Early-Pregnancy Dydrogesterone Supplementation Mimicking Luteal-Phase Support in ART Patients Did Not Provoke Major Reproductive Disorders in Pregnant Mice and Their Progeny
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Laura Jeschke, Clarisa Guillermina Santamaria, Nicole Meyer, Ana Claudia Zenclussen, Julia Bartley, and Anne Schumacher
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dydrogesterone ,early pregnancy ,artificial reproductive techniques ,luteal-phase support ,safety ,tolerability ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Progestogens are frequently administered during early pregnancy to patients undergoing assisted reproductive techniques (ART) to overcome progesterone deficits following ART procedures. Orally administered dydrogesterone (DG) shows equal efficacy to other progestogens with a higher level of patient compliance. However, potential harmful effects of DG on critical pregnancy processes and on the health of the progeny are not yet completely ruled out. We treated pregnant mice with DG in the mode, duration, and doses comparable to ART patients. Subsequently, we studied DG effects on embryo implantation, placental and fetal growth, fetal-maternal circulation, fetal survival, and the uterine immune status. After birth of in utero DG-exposed progeny, we assessed their sex ratios, weight gain, and reproductive performance. Early-pregnancy DG administration did not interfere with placental and fetal development, fetal-maternal circulation, or fetal survival, and provoked only minor changes in the uterine immune compartment. DG-exposed offspring grew normally, were fertile, and showed no reproductive abnormalities with the exception of an altered spermiogram in male progeny. Notably, DG shifted the sex ratio in favor of female progeny. Even though our data may be reassuring for the use of DG in ART patients, the detrimental effects on spermatogenesis in mice warrants further investigations and may be a reason for caution for routine DG supplementation in early pregnancy.
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- 2021
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42. miR155 Deficiency Reduces Myofibroblast Density but Fails to Improve Cardiac Function after Myocardial Infarction in Dyslipidemic Mouse Model
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David Schumacher, Adelina Curaj, Sakine Simsekyilmaz, Andreas Schober, Elisa A. Liehn, and Sebastian F. Mause
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microRNA ,cardiovascular disease ,myocardial infarction ,heart failure ,dyslipidemia ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Myocardial infarction remains the most common cause of heart failure with adverse remodeling. MicroRNA (miR)155 is upregulated following myocardial infarction and represents a relevant regulatory factor for cardiac remodeling by engagement in cardiac inflammation, fibrosis and cardiomyocyte hypertrophy. Here, we investigated the role of miR155 in cardiac remodeling and dysfunction following myocardial infarction in a dyslipidemic mouse model. Myocardial infarction was induced in dyslipidemic apolipoprotein E-deficient (ApoE−/−) mice with and without additional miR155 knockout by ligation of the LAD. Four weeks later, echocardiography was performed to assess left ventricular (LV) dimensions and function, and mice were subsequently sacrificed for histological analysis. Echocardiography revealed no difference in LV ejection fractions, LV mass and LV volumes between ApoE−/− and ApoE−/−/miR155−/− mice. Histology confirmed comparable infarction size and unaltered neoangiogenesis in the myocardial scar. Notably, myofibroblast density was significantly decreased in ApoE−/−/miR155−/− mice compared to the control, but no difference was observed for total collagen deposition. Our findings reveal that genetic depletion of miR155 in a dyslipidemic mouse model of myocardial infarction does not reduce infarction size and consecutive heart failure but does decrease myofibroblast density in the post-ischemic scar.
- Published
- 2021
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43. Infiltration of Immune Competent Cells into Primary Tumors and Their Surrounding Connective Tissues in Xenograft and Syngeneic Mouse Models
- Author
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Marlon Metzen, Michael Bruns, Wolfgang Deppert, and Udo Schumacher
- Subjects
cancer ,immune cell infiltration ,dendritic cells ,macrophages ,natural killer cells ,T cells ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
To fight cancer more efficiently with cell-based immunotherapy, more information about the cells of the immune system and their interaction with cancer cells in vivo is needed. Therefore paraffin wax embedded primary breast cancers from the syngeneic mouse WAP-T model and from xenografted tumors of breast, colon, melanoma, ovarian, neuroblastoma, pancreatic, prostate, and small cell lung cancer were investigated for the infiltration of immunocompetent cells by immunohistochemistry using antibodies against leukocyte markers. The following markers were used: CD45 as a pan-leukocyte marker, BSA-I as a dendritic cell marker, CD11b as an NK cell marker, and CD68 as a marker for macrophages. The labeled immune cells were attributed to the following locations: adjacent adipose tissue, tumor capsule, intra-tumoral septae, and cancer cells directly. In xenograft tumors, the highest score of CD45 and CD11b positive, NK, and dendritic cells were found in the adjacent adipose tissue, followed by lesser infiltration directly located at the cancer cells themselves. The detected numbers of CD45 positive cells differed between the tumor entities: few infiltrating cells in breast cancer, small cell lung cancer, neuroblastoma, a moderate infiltration in colon cancer, melanoma and ovarian cancer, strongest infiltration in prostate and pancreatic cancer. In the syngeneic tumors, the highest score of CD45 and CD11b positive, NK and dendritic cells were observed in the tumor capsule, followed by a lesser infiltration of the cancer tissue. Our findings argue for paying more attention to investigate how immune-competent cells can reach the tumor cells directly.
- Published
- 2021
- Full Text
- View/download PDF
44. Phosphatidylserine Supplementation as a Novel Strategy for Reducing Myocardial Infarct Size and Preventing Adverse Left Ventricular Remodeling
- Author
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David Schumacher, Adelina Curaj, Mareike Staudt, Franziska Cordes, Andreea R. Dumitraşcu, Benjamin Rolles, Christian Beckers, Josefin Soppert, Mihaela Rusu, Sakine Simsekyilmaz, Kinan Kneizeh, Chrishan J. A. Ramachandra, Derek J. Hausenloy, and Elisa A. Liehn
- Subjects
L-α-Phosphatidyl-L-serine ,phosphatidylserine ,myocardial infarction ,cardio-protection ,preconditioning ,inflammation ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Phosphatidylserines are known to sustain skeletal muscle activity during intense activity or hypoxic conditions, as well as preserve neurocognitive function in older patients. Our previous studies pointed out a potential cardioprotective role of phosphatidylserine in heart ischemia. Therefore, we investigated the effects of phosphatidylserine oral supplementation in a mouse model of acute myocardial infarction (AMI). We found out that phosphatidylserine increases, significantly, the cardiomyocyte survival by 50% in an acute model of myocardial ischemia-reperfusion. Similar, phosphatidylserine reduced significantly the infarcted size by 30% and improved heart function by 25% in a chronic model of AMI. The main responsible mechanism seems to be up-regulation of protein kinase C epsilon (PKC-ε), the main player of cardio-protection during pre-conditioning. Interestingly, if the phosphatidylserine supplementation is started before induction of AMI, but not after, it selectively inhibits neutrophil’s activation, such as Interleukin 1 beta (IL-1β) expression, without affecting the healing and fibrosis. Thus, phosphatidylserine supplementation may represent a simple way to activate a pre-conditioning mechanism and may be a promising novel strategy to reduce infarct size following AMI and to prevent myocardial injury during myocardial infarction or cardiac surgery. Due to the minimal adverse effects, further investigation in large animals or in human are soon possible to establish the exact role of phosphatidylserine in cardiac diseases.
- Published
- 2021
- Full Text
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45. Comparison of Hysteresis Based PWM Schemes ΔΣ-PWM and Direct Torque Control
- Author
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Kevin Klarmann, Malte Thielmann, and Walter Schumacher
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delta-sigma ,direct-torque-control ,switching frequency ,hysteresis comparator ,pulse-width-modulation ,comparison ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This paper presents the differences and similarities of ΔΣ-PWM as a hysteresis-based PWM scheme with direct torque control (DTC) using simulation models. The variable switching frequency caused by the hysteresis element is examined with regard to its instantaneous values. The comparison is based on an equal maximum switching frequency as a design criterion. With this first assumption, the variation of the instantaneous switching frequency is higher when using DTC because of the temporary prioritization of one inverter leg. Besides the lower variation, ΔΣ-PWM shows a higher average switching frequency. Because the switching frequency is related to the torque ripple, the usage of ΔΣ-PWM results in a smaller torque ripple. Due to the dependence of torque ripple on switching frequency, a second comparison is carried out based on the same average switching frequency. In this comparison the ΔΣ-PWM shows higher torque ripple than DTC.
- Published
- 2021
- Full Text
- View/download PDF
46. Impact of Horse Hoof Wall with Different Solid Surfaces
- Author
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Jing Zhao, Dan B. Marghitu, John Schumacher, and Wenzhong Wang
- Subjects
impact ,hoof wall ,friction ,horse ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This study aimed to investigate the impact of a horse hoof wall on three solid surfaces: steel, concrete and asphalt. Impact experiments were conducted for different impact angles and different initial impact velocities. The effect of impact surfaces, impact angles and initial impact velocities on the coefficient of restitution and the effective coefficient of friction were tested using one-way ANOVA. Analytical and numerical modeling of the impact were developed. The impact interval was divided into two phases: compression and restitution. For compression, a contact force with a damping term was used. The restitution was characterized by an elastic contact force. The stiffness and damping coefficients of the contact force were estimated from the normal impacts. The simulated velocities after the oblique impacts were compared to the velocities in the in vitro investigation. The coefficient of restitution varied significantly on different surfaces. The effective coefficient of friction was lower on steel compared to concrete and asphalt. The model presented in this study can be applied to refine the impact simulation of the equine hoof during locomotion.
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- 2020
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- View/download PDF
47. Large-scale vertical velocity, diabatic heating and drying profiles associated with seasonal and diurnal variations of convective systems observed in the GoAmazon2014/5 experiment
- Author
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S. Tang, S. Xie, Y. Zhang, M. Zhang, C. Schumacher, H. Upton, M. P. Jensen, K. L. Johnson, M. Wang, M. Ahlgrimm, Z. Feng, P. Minnis, and M. Thieman
- Subjects
Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This study describes the characteristics of large-scale vertical velocity, apparent heating source (Q1) and apparent moisture sink (Q2) profiles associated with seasonal and diurnal variations of convective systems observed during the two intensive operational periods (IOPs) that were conducted from 15 February to 26 March 2014 (wet season) and from 1 September to 10 October 2014 (dry season) near Manaus, Brazil, during the Green Ocean Amazon (GoAmazon2014/5) experiment. The derived large-scale fields have large diurnal variations according to convective activity in the GoAmazon region and the morning profiles show distinct differences between the dry and wet seasons. In the wet season, propagating convective systems originating far from the GoAmazon region are often seen in the early morning, while in the dry season they are rarely observed. Afternoon convective systems due to solar heating are frequently seen in both seasons. Accordingly, in the morning, there is strong upward motion and associated heating and drying throughout the entire troposphere in the wet season, which is limited to lower levels in the dry season. In the afternoon, both seasons exhibit weak heating and strong moistening in the boundary layer related to the vertical convergence of eddy fluxes. A set of case studies of three typical types of convective systems occurring in Amazonia – i.e., locally occurring systems, coastal-occurring systems and basin-occurring systems – is also conducted to investigate the variability of the large-scale environment with different types of convective systems.
- Published
- 2016
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48. Evolution of chlorophyll degradation is associated with plant transition to land
- Author
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Mareike Hauenstein, Isabel Schumacher, Damian Menghini, Serguei Ovinnikov, Nick Fankhauser, Sylvain Aubry, Stefan Hörtensteiner, Cyril Zipfel, and University of Zurich
- Subjects
Chlorophyll ,biology ,food and beverages ,Cell Biology ,Plant Science ,580 Plants (Botany) ,Plants ,biology.organism_classification ,Photosynthesis ,Chloroplast ,chemistry.chemical_compound ,Multicellular organism ,chemistry ,10126 Department of Plant and Microbial Biology ,Pigment accumulation ,Botany ,Genetics ,Arabidopsis thaliana ,Viridiplantae ,Adaptation ,10211 Zurich-Basel Plant Science Center - Abstract
Colonization of land by green plants (Viridiplantae) some 500 million years ago was made possible by large metabolic and biochemical adaptations. Chlorophyll, the central pigment of photosynthesis, is highly photo-active. In order to mitigate deleterious effects of pigment accumulation, some plants have evolved a coordinated pathway to deal with chlorophyll degradation end-products, so-called phyllobilins. This pathway has been so far mostly unravelled inArabidopsis thaliana. Here, large-scale comparative phylogenomic coupled to an innovative biochemical characterization strategy of phyllobilins allow a better understanding how such a pathway appeared in Viridiplantae. Our analysis reveals a stepwise evolution of the canonical pheophorbideamonooxygenase/phyllobilin pathway. It appears to have evolved gradually, first in chlorophyte’s chloroplasts, to ensure multicellularity by detoxifying chlorophyll catabolites, and in charophytes outside chloroplasts to allow adaptation of embryophytes to land. At least six out of the eight genes involved in the pathway were already present in the last common ancestor of green plants. This strongly suggests parallel evolution of distinct enzymes catalysing similar reactions in various lineages, particularly for the dephytylation step. Together, our study suggests that chlorophyll degradation accompanied the transition from water to land, and was therefore of great importance for plant diversification.
- Published
- 2022
49. Identification of a Hydroxypyrimidinone Compound (21) as a Potent APJ Receptor Agonist for the Potential Treatment of Heart Failure
- Author
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Wei Meng, Heather Finlay, Claudia Generaux, Chiuwa E. Luk, Tao Wang, Robert Paul Brigance, Joelle M. Onorato, Peter S. Gargalovic, Ruth R. Wexler, William A. Schumacher, Jeffrey S. Bostwick, Zulan Pi, and Karen A. Rossi
- Subjects
Agonist ,medicine.drug_class ,Pyrazole ,Pharmacology ,In vitro ,chemistry.chemical_compound ,chemistry ,Pharmacokinetics ,Pharmacodynamics ,Drug Discovery ,medicine ,Molecular Medicine ,Potency ,Receptor ,Apelin receptor - Abstract
This paper describes our continued efforts in the area of small-molecule apelin receptor agonists. Recently disclosed compound 2 showed an acceptable metabolic stability but demonstrated monodemethylation of the dimethoxyphenyl group to generate atropisomer metabolites in vitro. In this article, we extended the structure-activity relationship at the C2 position that led to the identification of potent pyrazole analogues with excellent metabolic stability. Due to the increased polarity at C2, the permeability for these compounds decreased. Further adjustment of the polarity by replacing the N1 2,6-dimethoxyphenyl group with a 2,6-diethylphenyl group and reoptimization for the potency of the C5 pyrroloamides resulted in potent compounds with improved permeability. Compound 21 displayed excellent pharmacokinetic profiles in rat, monkey, and dog models and robust pharmacodynamic efficacy in the rodent heart failure model. Compound 21 also showed an acceptable safety profile in preclinical toxicology studies and was selected as a backup development candidate for the program.
- Published
- 2021
50. Practical Application of Plan–Do–Check–Act Cycle for Quality Improvement of Sustainable Packaging: A Case Study
- Author
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Vi Nguyen, Nam Nguyen, Bastian Schumacher, and Thanh Tran
- Subjects
lean manufacturing ,PDCA ,sustainable packaging ,quality management ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The research aims to give practical instructions for applying Plan–Do–Check–Act (PDCA) cycle in a packaging process. Eco-friendly, recycled material and a new packaging method for quality improvement and cost efficiency of heavily fragile product packaging are studied in this paper. A case study was conducted at GPEM laboratory, Vietnamese German University, Vietnam. In this case study, the current packaging style with Styrofoam material was analyzed and replaced by new packaging material and methods after applying the PDCA cycle for continuous quality improvement. Targets of the research were to find the new packaging method using friendly environment materials, to improve the quality, and to reduce the defect ratio due to packaging for fine-stone round surface fountains. Moreover, the extra cost should not be higher than 20% compared with the current packaging cost. The article proposes a simplified way that focuses on the combination of quality tools in the PDCA multiple phases to solve these problems. The quality tools are applied effectively through the PDCA cycle from collecting data, defining, analysis, testing, evaluation, and making decisions. New packaging design was been produced and tested successfully. One hundred percent of new packaging boxes for the mid-weight fountains (under 15 kg) passed the dropping test condition. Nearly 10% of the heavier weight products (above 15 kg) still had some small cracks on their top and bottom due to drop tests. Another PDCA cycle is recommended to continue applying for achieving a thorough solution. The conducted results show that PDCA is an effective method to tackle the damage product issue due to inappropriate packaging material and technique. It also brings good solutions for balancing sustainable packaging improvement and reducing the cost to ensure profit for companies. Besides contributing a guide reference for PDCA deployment, the authors intend to inspire practitioners and researchers to broaden exploration of the PDCA applications for sustainable packaging methodology. The research analysis shows that the PDCA methodology should be applied for defect reduction and quality enhancement in the packaging field. The field currently lacks systematic guidance for continuous improvement.
- Published
- 2020
- Full Text
- View/download PDF
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