1,175 research outputs found
A Support Group for Inpatient Abused Adolescents
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75359/1/j.1744-6171.1990.tb00438.x.pd
Structural identification of oxidized acyl-phosphatidylcholines that induce platelet activation
Oxidation of low-density lipoprotein (LDL) generates proinflammatory and prothrombotic mediators that may play a crucial role in cardiovascular and inflammatory diseases. In order to study platelet-activating components of oxidized LDL 1-stearoyl-2-arachidonoyl-sn-glycero-3- phosphocholine, a representative of the major phospholipid species in LDL, the 1-acyl-phosphatidylcholines (PC), was oxidized by CuCl2 and H2O2. After separation by high-performance liquid chromatography, three compounds were detected which induced platelet shape change at low micromolar concentrations. Platelet activation by these compounds was distinct from the pathways stimulated by platelet-activating factor, lysophosphatidic acid, lyso-PC and thromboxane A(2), as evidenced by the use of specific receptor antagonists. Further analyses of the oxidized phospholipids by electrospray ionization mass spectrometry structurally identified them as 1-stearoyl-2-azelaoyl-sn-glycero-3-phosphocholine (m/z 694; SAzPC), 1-stearoyl-2-glutaroyl-snglycero-3- phosphocholine (m/z 638; SGPC), and 1-stearoyl-2-( 5-oxovaleroyl)-sn-glycero-3-phosphocholine (m/z 622; SOVPC). These observations demonstrate that novel 1-acyl-PC which had previously been found to stimulate interaction of monocytes with endothelial cells also induce platelet activation, a central step in acute thrombogenic and atherogenic processes. Copyright (C) 2005 S. Karger AG, Basel
Apoptotic Cells with Oxidation-specific Epitopes Are Immunogenic and Proinflammatory
Oxidation of low density lipoprotein (LDL) generates a variety of oxidatively modified lipids and lipid-protein adducts that are immunogenic and proinflammatory, which in turn contribute to atherogenesis. Cells undergoing apoptosis also display oxidized moieties on their surface membranes, as determined by binding of oxidation-specific monoclonal antibodies. In the present paper, we demonstrated by mass spectrometry that in comparison with viable cells, membranes of cells undergoing apoptosis contain increased levels of biologically active oxidized phospholipids (OxPLs). Indeed, immunization of mice with syngeneic apoptotic cells induced high autoantibody titers to various oxidation-specific epitopes of oxidized LDL, including OxPLs containing phosphorylcholine, whereas immunization with viable thymocytes, primary necrotic thymocytes, or phosphate-buffered saline did not. Reciprocally, these antisera specifically bound to apoptotic cells through the recognition of oxidation-specific epitopes. Moreover, splenocyte cultures from mice immunized with apoptotic cells spontaneously released significant levels of T helper cell (Th) 1 and Th2 cytokines, whereas splenocytes from controls yielded only low levels. Finally, we demonstrated that the OxPLs of apoptotic cells activated endothelial cells to induce monocyte adhesion, a proinflammatory response that was abrogated by an antibody specific to oxidized phosphatidylcholine. These results suggest that apoptotic cell death generates oxidatively modified moieties, which can induce autoimmune responses and a local inflammatory response by recruiting monocytes via monocyte–endothelial cell interaction
Better Nonlinear Models from Noisy Data: Attractors with Maximum Likelihood
A new approach to nonlinear modelling is presented which, by incorporating
the global behaviour of the model, lifts shortcomings of both least squares and
total least squares parameter estimates. Although ubiquitous in practice, a
least squares approach is fundamentally flawed in that it assumes independent,
normally distributed (IND) forecast errors: nonlinear models will not yield IND
errors even if the noise is IND. A new cost function is obtained via the
maximum likelihood principle; superior results are illustrated both for small
data sets and infinitely long data streams.Comment: RevTex, 11 pages, 4 figure
A Comparative Study of Some Pseudorandom Number Generators
We present results of an extensive test program of a group of pseudorandom
number generators which are commonly used in the applications of physics, in
particular in Monte Carlo simulations. The generators include public domain
programs, manufacturer installed routines and a random number sequence produced
from physical noise. We start by traditional statistical tests, followed by
detailed bit level and visual tests. The computational speed of various
algorithms is also scrutinized. Our results allow direct comparisons between
the properties of different generators, as well as an assessment of the
efficiency of the various test methods. This information provides the best
available criterion to choose the best possible generator for a given problem.
However, in light of recent problems reported with some of these generators, we
also discuss the importance of developing more refined physical tests to find
possible correlations not revealed by the present test methods.Comment: University of Helsinki preprint HU-TFT-93-22 (minor changes in Tables
2 and 7, and in the text, correspondingly
Business unusual: collective action against bribery in international business
Collective action initiatives in which governments and companies make anti-corruption commitments have proliferated in recent years. This apparently prosocial behavior defies the logic of collective action and, given that bribery often goes undetected and unpunished, is not easily explained by principal-agent theory. Club theory suggests that the answer lies in the institutional design of anti-corruption clubs: collective action can work as long as membership has high entry costs, members receive selective benefits, and compliance is adequately policed. This article contributes to the debate by examining how these conditions manifest in the case of anti-corruption clubs in the realm of international business, with particular focus on the international dimension of many initiatives. This vertical aspect of institutional design creates a richer, more complex set of reputational and material benefits for members, as well as allowing for more credible and consistent monitoring and enforcement
The Evolution of the Market of the Hungarian Printing Industry after 1989: The End of a Success Story?
Inflammatory bowel disease and fatigue: the effect of physical activity and/or omega-3 supplementation
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