130,355 research outputs found
The immunological relationship between filtrable agent, Salmonella and murine leukosis
Salmonella typhimurium was invariably isolated from our J strain murine leukosis. Immunization of D103 mice with either inactivated Salmonella typhimurium or the cell-free extract of leukosis inhibited the transplantation of leukosis. The adoptive immunization of D103 mice with spleen cells of Strong A mice immunized with either Salmonella or the cell-free extract of leukosis inhibited the transplantation of leukosis. The addition of either Salmonella or the cell-free extract of leukosis inhibited the migration of macrophages of leukosis spleen in tissue culture. Strong A mice is non-susceptible to J strain leukosis. However, inoculation of neonatal Strong A mice with the cell-free extract of leukosis produced a susceptibility to the transplantation of leukosis. These results suggest that both a filtrable agent and Salmonella typhimurium are present in cells of this leukosis and might be etiologically related to the leukosis.</p
P-Selectivity, Immunity, and the Power of One Bit
We prove that P-sel, the class of all P-selective sets, is EXP-immune, but is
not EXP/1-immune. That is, we prove that some infinite P-selective set has no
infinite EXP-time subset, but we also prove that every infinite P-selective set
has some infinite subset in EXP/1. Informally put, the immunity of P-sel is so
fragile that it is pierced by a single bit of information.
The above claims follow from broader results that we obtain about the
immunity of the P-selective sets. In particular, we prove that for every
recursive function f, P-sel is DTIME(f)-immune. Yet we also prove that P-sel is
not \Pi_2^p/1-immune
Mathematical models for vaccination, waning immunity and immune system boosting: a general framework
When the body gets infected by a pathogen or receives a vaccine dose, the
immune system develops pathogen-specific immunity. Induced immunity decays in
time and years after recovery/vaccination the host might become susceptible
again. Exposure to the pathogen in the environment boosts the immune system
thus prolonging the duration of the protection. Such an interplay of within
host and population level dynamics poses significant challenges in rigorous
mathematical modeling of immuno-epidemiology. The aim of this paper is twofold.
First, we provide an overview of existing models for waning of
disease/vaccine-induced immunity and immune system boosting. Then a new
modeling approach is proposed for SIRVS dynamics, monitoring the immune status
of individuals and including both waning immunity and immune system boosting.
We show that some previous models can be considered as special cases or
approximations of our framework.Comment: 18 pages, 1 figure keywords: Immuno-epidemiology, Waning immunity,
Immune status, Boosting, Physiological structure, Reinfection, Delay
equations, Vaccination. arXiv admin note: substantial text overlap with
arXiv:1411.319
Overextending Immunity: Arbitral Institutional Liability in the United States, England, and France
This Note examines the relationship between the arbitral institution and the disputing parties. Part I demonstrates the decisions parties face when choosing between traditional litigation and arbitration; it also discusses the differences between an arbitral institution and an ad hoc arbitration, as well as major arbitral institutions\u27 rules regarding their own liability. Part II introduces several nations\u27 approaches to judicial immunity, and how it is applied to arbitrators and arbitral institutions. Part II also weighs differing views on how to characterize the relationship between disputing parties and the arbitral institution. Finally, Part II discusses several key criticisms to the immunity of arbitral institutions. Part III will demonstrate the need for arbitral institutions\u27 contractual liability to disputing parties, and will address several potential criticisms and policy concerns of this approach
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PACAP neuropeptide promotes Hepatocellular Protection via CREB-KLF4 dependent autophagy in mouse liver Ischemia Reperfusion Injury.
Organ ischemia reperfusion injury (IRI), associated with acute hepatocyte death, remains an unresolved problem in clinical orthotopic liver transplantation (OLT). Autophagy, an intracellular self-digesting progress, is responsible for cell reprograming required to regain post-stress homeostasis. Methods: Here, we analyzed the cytoprotective mechanism of pituitary adenylate cyclase-activating polypeptide (PACAP)-promoted hepatocellular autophagy in a clinically relevant mouse model of extended hepatic cold storage (4 °C UW solution for 20 h) followed by syngeneic OLT. Results: In contrast to 41.7% of liver graft failure by day 7 post-transplant in control group, PACAP treatment significantly improved graft survival (91.7% by day 14), and promoted autophagy-associated regeneration programs in OLT. In parallel in vitro studies, PACAP-enhanced autophagy ameliorated cellular damage (LDH/ALT levels), and diminished necrosis in H2O2-stressed primary hepatocytes. Interestingly, PACAP not only induced nuclear cAMP response element-binding protein (CREB), but also triggered reprogramming factor Kruppel-like factor 4 (KLF4) expression in IR-stressed OLT. Indeed, CREB inhibition attenuated hepatic autophagy and recreated hepatocellular injury in otherwise PACAP-protected livers. Furthermore, CREB inhibition suppressed PACAP-induced KLF4 expression, whereas KLF4 blockade abolished PACAP-promoted autophagy and neutralized PACAP-mediated hepatoprotection both in vivo and in vitro. Conclusion: Current study documents the essential neural regulation of PACAP-promoted autophagy in hepatocellular homeostasis in OLT, which provides the emerging therapeutic principle to combat hepatic IRI in OLT
The Effect of Disease-induced Mortality on Structural Network Properties
As the understanding of the importance of social contact networks in the
spread of infectious diseases has increased, so has the interest in
understanding the feedback process of the disease altering the social network.
While many studies have explored the influence of individual epidemiological
parameters and/or underlying network topologies on the resulting disease
dynamics, we here provide a systematic overview of the interactions between
these two influences on population-level disease outcomes. We show that the
sensitivity of the population-level disease outcomes to the combination of
epidemiological parameters that describe the disease are critically dependent
on the topological structure of the population's contact network. We introduce
a new metric for assessing disease-driven structural damage to a network as a
population-level outcome. Lastly, we discuss how the expected individual-level
disease burden is influenced by the complete suite of epidemiological
characteristics for the circulating disease and the ongoing process of network
compromise. Our results have broad implications for prediction and mitigation
of outbreaks in both natural and human populations.Comment: 23 pages, 6 figure
Identification of Class I HLA T Cell Control Epitopes for West Nile Virus
The recent West Nile virus (WNV) outbreak in the United States underscores the importance of understanding human immune responses to this pathogen. Via the presentation of viral peptide ligands at the cell surface, class I HLA mediate the T cell recognition and killing of WNV infected cells. At this time, there are two key unknowns in regards to understanding protective T cell immunity: 1) the number of viral ligands presented by the HLA of infected cells, and 2) the distribution of T cell responses to these available HLA/viral complexes. Here, comparative mass spectroscopy was applied to determine the number of WNV peptides presented by the HLA-A*11:01 of infected cells after which T cell responses to these HLA/WNV complexes were assessed. Six viral peptides derived from capsid, NS3, NS4b, and NS5 were presented. When T cells from infected individuals were tested for reactivity to these six viral ligands, polyfunctional T cells were focused on the GTL9 WNV capsid peptide, ligands from NS3, NS4b, and NS5 were less immunogenic, and two ligands were largely inert, demonstrating that class I HLA reduce the WNV polyprotein to a handful of immune targets and that polyfunctional T cells recognize infections by zeroing in on particular HLA/WNV epitopes. Such dominant HLA/peptide epitopes are poised to drive the development of WNV vaccines that elicit protective T cells as well as providing key antigens for immunoassays that establish correlates of viral immunity. © 2013 Kaabinejadian et al
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