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Search Results: 1 - 10 of 189866 matches for " Günter Lochnit "
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Collagen Metabolism of Human Osteoarthritic Articular Cartilage as Modulated by Bovine Collagen Hydrolysates
Saskia Schadow, Hans-Christian Siebert, Günter Lochnit, Jens Kordelle, Markus Rickert, Jürgen Steinmeyer
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0053955
Abstract: Destruction of articular cartilage is a characteristic feature of osteoarthritis (OA). Collagen hydrolysates are mixtures of collagen peptides and have gained huge public attention as nutriceuticals used for prophylaxis of OA. Here, we evaluated for the first time whether different bovine collagen hydrolysate preparations indeed modulate the metabolism of collagen and proteoglycans from human OA cartilage explants and determined the chemical composition of oligopeptides representing collagen fragments. Using biophysical techniques, like MALDI-TOF-MS, AFM, and NMR, the molecular weight distribution and aggregation behavior of collagen hydrolysates from bovine origin (CH-Alpha?, Peptan? B 5000, Peptan? B 2000) were determined. To investigate the metabolism of human femoral OA cartilage, explants were obtained during knee replacement surgery. Collagen synthesis of explants as modulated by 0–10 mg/ml collagen hydrolysates was determined using a novel dual radiolabeling procedure. Proteoglycans, NO, PGE2, MMP-1, -3, -13, TIMP-1, collagen type II, and cell viability were determined in explant cultures. Groups of data were analyzed using ANOVA and the Friedman test (n = 5–12). The significance was set to p≤0.05. We found that collagen hydrolysates obtained from different sources varied with respect to the width of molecular weight distribution, average molecular weight, and aggregation behavior. None of the collagen hydrolysates tested stimulated the biosynthesis of collagen. Peptan? B 5000 elevated NO and PGE2 levels significantly but had no effect on collagen or proteoglycan loss. All collagen hydrolysates tested proved not to be cytotoxic. Together, our data demonstrate for the first time that various collagen hydrolysates differ with respect to their chemical composition of collagen fragments as well as by their pharmacological efficacy on human chondrocytes. Our study underscores the importance that each collagen hydrolysate preparation should first demonstrate its pharmacological potential both in vitro and in vivo before being used for both regenerative medicine and prophylaxis of OA.
The Wnt Pathway Controls Cell Death Engulfment, Spindle Orientation, and Migration through CED-10/Rac
Juan Cabello,Lukas J. Neukomm,Ufuk Günesdogan,Katharina Burkart,Steve J. Charette,Günter Lochnit,Michael O. Hengartner,Ralf Schnabel
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.1000297
Abstract: Wnt signalling pathways have extremely diverse functions in animals, including induction of cell fates or tumours, guidance of cell movements during gastrulation, and the induction of cell polarity. Wnt can induce polar changes in cellular morphology by a remodelling of the cytoskeleton. However, how activation of the Frizzled receptor induces cytoskeleton rearrangement is not well understood. We show, by an in depth 4-D microscopy analysis, that the Caenorhabditis elegans Wnt pathway signals to CED-10/Rac via two separate branches to regulate modulation of the cytoskeleton in different cellular situations. Apoptotic cell clearance and migration of the distal tip cell require the MOM-5/Fz receptor, GSK-3 kinase, and APC/APR-1, which activate the CED-2/5/12 branch of the engulfment machinery. MOM-5 (Frizzled) thus can function as an engulfment receptor in C. elegans. Our epistatic analyses also suggest that the two partially redundant signalling pathways defined earlier for engulfment may act in a single pathway in early embryos. By contrast, rearrangement of mitotic spindles requires the MOM-5/Fz receptor, GSK-3 kinase, and β-catenins, but not the downstream factors LIT-1/NLK or POP-1/Tcf. Taken together, our results indicate that in multiple developmental processes, CED-10/Rac can link polar signals mediated by the Wnt pathway to rearrangements of the cytoskeleton.
The Wnt Pathway Controls Cell Death Engulfment, Spindle Orientation, and Migration through CED-10/Rac
Juan Cabello,Lukas J. Neukomm,Ufuk Günesdogan,Katharina Burkart,Steve J. Charette,Günter Lochnit,Michael O. Hengartner,Ralf Schnabel
PLOS Biology , 2010, DOI: 10.1371/journal.pbio.1000297
Abstract: Wnt signalling pathways have extremely diverse functions in animals, including induction of cell fates or tumours, guidance of cell movements during gastrulation, and the induction of cell polarity. Wnt can induce polar changes in cellular morphology by a remodelling of the cytoskeleton. However, how activation of the Frizzled receptor induces cytoskeleton rearrangement is not well understood. We show, by an in depth 4-D microscopy analysis, that the Caenorhabditis elegans Wnt pathway signals to CED-10/Rac via two separate branches to regulate modulation of the cytoskeleton in different cellular situations. Apoptotic cell clearance and migration of the distal tip cell require the MOM-5/Fz receptor, GSK-3 kinase, and APC/APR-1, which activate the CED-2/5/12 branch of the engulfment machinery. MOM-5 (Frizzled) thus can function as an engulfment receptor in C. elegans. Our epistatic analyses also suggest that the two partially redundant signalling pathways defined earlier for engulfment may act in a single pathway in early embryos. By contrast, rearrangement of mitotic spindles requires the MOM-5/Fz receptor, GSK-3 kinase, and β-catenins, but not the downstream factors LIT-1/NLK or POP-1/Tcf. Taken together, our results indicate that in multiple developmental processes, CED-10/Rac can link polar signals mediated by the Wnt pathway to rearrangements of the cytoskeleton.
Vaccine-induced antibodies linked to bovine neonatal pancytopenia (BNP) recognize cattle major histocompatibility complex class I (MHC I)
Fabian Deutskens, Benjamin Lamp, Christiane M Riedel, Eveline Wentz, Günter Lochnit, Klaus Doll, Heinz-Jürgen Thiel, Till Rümenapf
Veterinary Research , 2011, DOI: 10.1186/1297-9716-42-97
Abstract: A mysterious hemorrhagic disease of cattle emerged in 2007 affecting solely newborn calves [1]. First named "blood sweating", "hemorrhagic diathesis" and "bleeding calf syndrome" it was finally designated "bovine neonatal pancytopenia" (BNP) at the Satellite Symposium of the European Buiatric Congress in 2009 [2]. During the last years an increasing number of calves were affected by this syndrome. BNP cases were reported for several breeds and both genders are affected equally. Reports of BNP affected calves are known from several European countries including France, Germany, United Kingdom, Ireland, Netherlands, Belgium, Luxembourg, Italy, and Spain [2,3]. The disease is unknown in countries which do not vaccinate against bovine virus diarrhea virus (BVDV) like Denmark, Austria, and Switzerland [4].BNP is characterized by severe external and internal hemorrhages. Clinical studies have shown that the bleedings are caused by a massive thrombocytopenia, usually connected with a severe leukopenia and depletion of bone marrow cells, the latter may result in complete aplasia [1,5-7]. Mortality is up to 90% in affected calves; mild to subclinical manifestations are rarely observed [8].In the past, bleeding disorders in cattle due to thrombocytopenia have been described primarily as a consequence of intoxications and viral infections, but sporadic cases were also linked to bacterial septicemia, hereditary diseases or immune mediated processes [9]. Several hypotheses have been put forward with regard to the etiology of BNP, such as bacterial and virus infections (BVDV, bluetongue virus, porcine circovirus 2 [9]) or intoxications but could not be confirmed [1,8,10]. A genetic etiology of BNP was discussed, but BNP appearance showed no link to certain genotypes. Epidemiological studies showed that mutations in coagulation factor XI [11] or certain MHC class II haplotypes [12] were not associated with BNP outbreaks. In BNP affected calves, the often dramatic decline of thrombo
Domain Decomposition of an Optimal Control Problem for Semi-Linear Elliptic Equations on Metric Graphs with Application to Gas Networks  [PDF]
Günter Leugering
Applied Mathematics (AM) , 2017, DOI: 10.4236/am.2017.88082
Abstract: We consider optimal control problems for the flow of gas in a pipe network. The equations of motions are taken to be represented by a semi-linear model derived from the fully nonlinear isothermal Euler gas equations. We formulate an optimal control problem on a given network and introduce a time discretization thereof. We then study the well-posedness of the corresponding time-discrete optimal control problem. In order to further reduce the complexity, we consider an instantaneous control strategy. The main part of the paper is concerned with a non-overlapping domain decomposition of the semi-linear elliptic optimal control problem on the graph into local problems on a small part of the network, ultimately on a single edge.
The Significance of Solutions Obtained from Ill-Posed Systems of Linear Equations Constituted by Synchrotron Radiation Based Anomalous Small-Angle X-Ray Scattering  [PDF]
Günter Johannes Goerigk
Advances in Linear Algebra & Matrix Theory (ALAMT) , 2018, DOI: 10.4236/alamt.2018.81007
Abstract: Synchrotron radiation based experimental techniques known as Anomalous Small-Angle X-ray Scattering (ASAXS) provide deep insight into the nanostructure of uncountable material systems in condensed matter research i.e. solid state physics, chemistry, engineering and life sciences thereby rendering the origin of the macroscopic functionalization of the various materials via correlation to its structural architecture on a nanometer length scale. The techniques constitute a system of linear equations, which can be treated by matrix theory. The study aims to analyze the significance of the solutions of the stated matrix equations by use of the so-called condition numbers first introduced by A. Turing, J. von Neumann and H. Goldstine. Special attention was given for the comparison with direct methods i.e. the Gaussian elimination method. The mathematical roots of ill-posed ASAXS equations preventing matrix inversion have been identified. In the framework of the theory of von Neumann and Goldstine the inversion of certain matrices constituted by ASAXS gradually becomes impossible caused by non-definiteness. In Turing’s theory which starts from more general prerequisites, the principal minors of the same matrices approach singularity thereby imposing large errors on inversion. In conclusion both theories recommend for extremely ill-posed ASAXS problems avoiding inversion and the use of direct methods for instance Gaussian elimination.
On Henig Regularization of Material Design Problems for Quasi-Linear p-Biharmonic Equation  [PDF]
Peter Kogut, Günter Leugering, Ralph Schiel
Applied Mathematics (AM) , 2016, DOI: 10.4236/am.2016.714134
Abstract: We study a Dirichlet optimal design problem for a quasi-linear monotone p-biharmonic equation with control and state constraints. We take the coefficient of the p-biharmonic operator as a design variable in \"\". In this article, we discuss the relaxation of such problem.
ALTSTADTERNEUERUNG IN DEUTSCHLAND
MERTINS,GüNTER;
Investigación y Desarrollo , 2008,
Abstract: in a very brief presentation the author acknowledges the reasons behind the renovation of the historical towns in the old west germany followed by the legal foundation, efforts and public financing and the results that came from that process. it is in this context that some municipalities played a central role in the conservation efforts by emphasizing their political action in the functional revitalization of their cities and the resulting economic growth. to finish the author makes reference to similar processes in the old east germany after the reunification, a process that was largely funded by the subsidies from the european union.
Of empty thoughts and blind intuitions Kant's answer to McDowell
Z?ller, Günter;
Trans/Form/A??o , 2010, DOI: 10.1590/S0101-31732010000100005
Abstract: this paper examines the relation between intuition and concept in kant in light of john mcdowell's neo-kantian position that intuitions are concept-laden.2 the focus is on kant's twofold pronouncement that thoughts without content are empty and that intuitions without concepts are blind. i show that intuitions as singular representations are not instances of passive data intake but the result of synthetic unification of the given manifold of the senses by the power of the imagination under the guidance of the understanding. against mcdowell i argue that the amenability of intuitions to conceptual determination is not due some pre-existing, absolute conceptuality of the real but to the "work of the subject."3 on a more programmatic level, this paper seeks to demonstrate the limitations of a selective appropriation of kant and the philosophical potential of a more comprehensive and thorough consideration of his work. section 1 addresses the unique balance in kant's philosophy between the work on particular problems and the orientation toward a systematic whole. section 2 outlines mcdowell's take on the kantian distinction between intuition and concept in the context of the kant readings by sellars and strawson. section 3 exposes mcdowell's relapse into the myth of the given. section 4 proposes a reading of kant's theoretical philosophy as an epistemology of metaphysical cognition. section 5 details kant's original account of sensible intuition in the inaugural-dissertation of 1770. section 6 presents the transition from the manifold of the senses to the synthesis in the imagination and the unification through the categories in the critique of pure reason (1781 and 1787). section 7 addresses kant's formalism in epistemology and metaphysics.
Limnología de un Lago Tropical de Alta Monta?a, en Ecuador: características de los sedimentos y tasa de sedimentación
Gunkel,Günter;
Revista de Biología Tropical , 2003,
Abstract: equatorial high mountain lakes are a special type of lake occurring mainly in the south american andes as well as in central africa and asia. they occur at altitudes of a few thousand meters above sea level and are cold-water lakes (< 20°c). relatively little is known about them. a long-term limnological study was therefore undertaken at lake san pablo, ecuador, to analyze the basic limnological processes of the lake, which has a tendency for eutrophication. sediment quality of san pablo lake is given under consideration of horizontal and vertical distribution using sediment cores. significance of sediments for eutrophication process of lakes is demonstrated using phosphorus concentration of sediments as well as the phosphorus retention capacity of the sediments by ratio fe/p. dating of the sediments is done using 137cs and 210pb, but the activity of 137cs in the sediment was very low nearly at the detection level. sedimentation rate is determined to be 3.5 mm/year and the sediment cores represent about 110 years. p concentration of the sediments is high (~ 5 g/kg dry substance), and p retention capacity by fe is insufficient (fe/p = 4). the sediment quality did not change significantly during the past decades, and the trophic state of san pablo lake was already less or more eutrophic 110 years ago. the contamination of the lake sediments by heavy metals is insignificant.
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