78 research outputs found
Reduction of Vector and Axial--Vector Fields in a Bosonized Nambu--Jona--Lasinio Model
We derive the effective action for pseudoscalar mesons by integrating out
vector and axial--vector collective fields in the generating functional of the
bosonized NJL--model. The corresponding modifications of the nonlinear
effective Lagrangian and the bosonized currents, arising at , are
discussed.Comment: 30p. 1 fig. on reques
Radiative Kaon Decays and Violation
The amplitudes of and decays have been calculated within chiral
Lagrangian approach including higher-order derivative terms and meson loops.
The selfconsistency of the simultaneous description of the experimental data on
the nonleptonic and radiative kaon decays have been demonstrated. We estimate
the effects of ``indirect'' and ``direct'' -violation in decays and discuss -violating charge asymmetries in decays.Comment: 25 p., DESY 93-06
On the --corrections to decay amplitudes in nonlinear and linear chiral models
The calculations of isotopic amplitudes and their results for the direct
--violating charge asymmetry in decays within the
nonlinear and linear (--model) chiral Lagrangian approach are compared
with each other. It is shown, that the latter, taking into account intermediate
scalar resonances, does not reproduce the --corrections of the nonlinear
approach introduced by Gasser and Leutwyler, being saturated mainly by vector
resonance exchange. The resulting differences concerning the violation
effect are traced in some detail.Comment: 14 page
Heat-Kernel Calculation of Quark Determinant and Computer Algebra
In this paper there we describe the calculational background of deriving a
strong meson Lagrangian from the Nambu--Jona-Lasinio quark model using the
computer algebra systems FORM and REDUCE in recursive algorithms, based on the
heat-kernel method for the calculation of the quark determinant.Comment: LATEX, 11 p., DESY 92-15
Uropathogenic Escherichia coli virulence and innate immune responses during urinary tract infection
Urinary tract infections (UTI) are among the most common infectious diseases of humans and are the most common nosocomial infections in the developed world. It is estimated that 40-50% of women and 5% of men will develop a UTI in their lifetime, and UTI accounts for more than 1 million hospitalizations and $1.6 billion in medical expenses each year in the USA. Uropathogenic Escherichia coli (UPEC) is the primary cause of UTI. This review presents an overview of recent discoveries related to the primary virulence factors of UPEC and major innate immune responses to infection of the lower urinary tract. New and emerging themes in UPEC research are discussed in the context of the interface between host and pathogen
Calculation of Heat-Kernel Coefficients and Usage of Computer Algebra
The calculation of heat-kernel coefficients with the classical DeWitt
algorithm has been discussed. We present the explicit form of the coefficients
up to in the general case and up to for the minimal parts.
The results are compared with the expressions in other papers. A method to
optimize the usage of memory for working with large expressions on universal
computer algebra systems has been proposed.Comment: 12 pages, LaTeX, no figures. Extended version of contribution to
AIHENP'95, Pisa, April 3-8, 199
On the Origin of the Enhancementof CP-violating Charge Asymmetries in Decays Predicted from Chiral Theory
We present an analysis of the enhancement of CP-violating charge asymmetries
in decays. Calculations of decay amplitudes are performed
on the basis of bosonized strong and weak Lagrangians derived from
QCD-motivated quark Lagrangians. We show that the interplay of fourth-order
contributions of chiral Lagrangians for strong interactions and penguin
operators in weak interactions significantly enhances the charge asymmetries.Comment: DESY 92-106, 15
The co-transcriptome of uropathogenic Escherichia coli-infected mouse macrophages reveals new insights into host-pathogen interactions
© 2014 The Authors. Cellular Microbiology published by John Wiley & Sons Ltd. Urinary tract infections (UTI) are among the most common infections in humans. Uropathogenic Escherichia coli (UPEC) can invade and replicate within bladder epithelial cells, and some UPEC strains can also survive within macrophages. To understand the UPEC transcriptional programme associated with intramacrophage survival, we performed host-pathogen co-transcriptome analyses using RNA sequencing. Mouse bone marrow-derived macrophages (BMMs) were challenged over a 24h time course with two UPEC reference strains that possess contrasting intramacrophage phenotypes: UTI89, which survives in BMMs, and 83972, which is killed by BMMs. Neither of these strains caused significant BMM cell death at the low multiplicity of infection that was used in this study. We developed an effective computational framework that simultaneously separated, annotated and quantified the mammalian and bacterial transcriptomes. Bone marrow-derived macrophages responded to the two UPEC strains with a broadly similar gene expression programme. In contrast, the transcriptional responses of the UPEC strains diverged markedly from each other. We identified UTI89 genes up-regulated at 24h post-infection, and hypothesized that some may contribute to intramacrophage survival. Indeed, we showed that deletion of one such gene (pspA) significantly reduced UTI89 survival within BMMs. Our study provides a technological framework for simultaneously capturing global changes at the transcriptional level in co-cultures, and has generated new insights into the mechanisms that UPEC use to persist within the intramacrophage environment
Strain- and host species-specific inflammasome activation, IL-1β release, and cell death in macrophages infected with uropathogenic Escherichia coli.
Uropathogenic Escherichia coli (UPEC) is the main etiological agent of urinary tract infections (UTIs). Little is known about interactions between UPEC and the inflammasome, a key innate immune pathway. Here we show that UPEC strains CFT073 and UTI89 trigger inflammasome activation and lytic cell death in human macrophages. Several other UPEC strains, including two multidrug-resistant ST131 isolates, did not kill macrophages. In mouse macrophages, UTI89 triggered cell death only at a high multiplicity of infection, and CFT073-mediated inflammasome responses were completely NLRP3-dependent. Surprisingly, CFT073- and UTI89-mediated responses only partially depended on NLRP3 in human macrophages. In these cells, NLRP3 was required for interleukin-1 beta (IL-1 beta) maturation, but contributed only marginally to cell death. Similarly, caspase-1 inhibition did not block cell death in human macrophages. In keeping with such differences, the pore-forming toxin a-hemolysin mediated a substantial proportion of CFT073-triggered IL-1 beta secretion in mousebut nothumanmacrophages. There wasalso a more substantial alpha-hemolysin-independent cell death response in human vs. mouse macrophages. Thus, in mouse macrophages, CFT073-triggered inflammasome responses are completely NLRP3-dependent, and largely alpha-hemolysin-dependent. In contrast, UPEC activates an NLRP3-independent cell death pathway and an alpha-hemolysin-independent IL-1 beta secretion pathway in human macrophages. This has important implications for understanding UTI in humans
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