Development of 2nd generation aminomethyl spectinomycins that overcome native efflux in Mycobacterium abscessus

Mycobacterium abscessus (Mab), a nontuberculous mycobacterial (NTM) species, is an emerging pathogen with high intrinsic drug resistance. Current standard-of-care therapy results in poor outcomes, demonstrating the urgent need to develop effective antimycobacterial regimens. Through synthetic modification of spectinomycin (SPC), we have identified a distinct structural subclass of N-ethylene linked aminomethyl SPCs (eAmSPCs) that are up to 64-fold more potent against Mab over the parent SPC. Mechanism of action and crystallography studies demonstrate that the eAmSPCs display a mode of ribosomal inhibition consistent with SPC. However, they exert their increased antimicrobial activity through enhanced accumulation, largely by circumventing efflux mechanisms. The N-ethylene linkage within this series plays a critical role in avoiding TetV-mediated efflux, as lead eAmSPC 2593 displays a mere fourfold susceptibility improvement against Mab ΔtetV, in contrast to the 64-fold increase for SPC. Even a minor shortening of the linkage by a single carbon, akin to 1st generation AmSPC 1950, results in a substantial increase in MICs and a 16-fold rise in susceptibility against Mab ΔtetV. These shifts suggest that longer linkages might modify the kinetics of drug expulsion by TetV, ultimately shifting the equilibrium towards heightened intracellular concentrations and enhanced antimicrobial efficacy. Furthermore, lead eAmSPCs were also shown to synergize with various classes of anti-Mab antibiotics and retain activity against clinical isolates and other mycobacterial strains. Encouraging pharmacokinetic profiles coupled with robust efficacy in Mab murine infection models suggest that eAmSPCs hold the potential to be developed into treatments for Mab and other NTM infections

Spiking Patterns and Their Functional Implications in the Antennal Lobe of the Tobacco Hornworm Manduca sexta

Bursting as well as tonic firing patterns have been described in various sensory systems. In the olfactory system, spontaneous bursts have been observed in neurons distributed across several synaptic levels, from the periphery, to the olfactory bulb (OB) and to the olfactory cortex. Several in vitro studies indicate that spontaneous firing patterns may be viewed as “fingerprints” of different types of neurons that exhibit distinct functions in the OB. It is still not known, however, if and how neuronal burstiness is correlated with the coding of natural olfactory stimuli. We thus conducted an in vivo study to probe this question in the OB equivalent structure of insects, the antennal lobe (AL) of the tobacco hornworm Manduca sexta. We found that in the moth's AL, both projection (output) neurons (PNs) and local interneurons (LNs) are spontaneously active, but PNs tend to produce spike bursts while LNs fire more regularly. In addition, we found that the burstiness of PNs is correlated with the strength of their responses to odor stimulation – the more bursting the stronger their responses to odors. Moreover, the burstiness of PNs was also positively correlated with the spontaneous firing rate of these neurons, and pharmacological reduction of bursting resulted in a decrease of the neurons' responsiveness. These results suggest that neuronal burstiness reflects a physiological state of these neurons that is directly linked to their response characteristics

The politics of the adjective global : May’s global Britain and the ‘new world’

The adjective global has come to be an omnipresent ingredient of contemporary politics discourses. There is hardly anything these days that is not attributed with this adjective in one context or another. Most recently, in the context of the Brexit-debate, “Britain” has been relaunched by UK Prime Minister May as “global Britain”. This chapter engages with the adjective global. It argues that the omnipresence of the adjective global is not just a linguistic curiosity, nor is it “simply” a symbolic manifestation of a “global” consciousness. Rather, the widespread use of global is a political phenomenon. It constitutes the discursive reproduction of a web of meanings that is best labelled “new world”. As such, the use of the adjective global demands critical scrutiny from political analysts. The aim of the chapter is twofold. First, it outlines this theoretical argument. Second, it discusses the politics of the adjective global in UK Prime Minister Theresa May’s post-Brexit use of the term ‘global Britain’

High Precision Electron Beam Diagnostic System for High Current Long Pulse Beams

As part of the effort to develop a multi-axis electron beam transport system using stripline kicker technology for DARHT II apploications, it is necessary to precisely determine the position and extent of long high energy beams (6-40 MeV, 1-4 kA, 2 microseconds) for accurate position control. The kicker positioning system utilizes shot-to-shot adjustments for reduction of relatively slow (<20 MHz) motion of the beam centroid. The electron beams passing through the diagnostic systems have the potential for large halo effects that tend to corrupt measurements performed using capacitive pickoff probes. Likewise, transmission line traveling wave probes have problems with multi-bounce effects due to these longer pulse widths. Finally, the high energy densities experienced in these applications distort typical foil beam position measurements

The ‘bubbling up’ of subterranean politics in Europe

This article presents the findings of a collaborative research project involving seven field teams across Europe investigating a range of new political phenomena termed 'subterranean politics'. The article argues that the social mobilizations and collective activities in 2011 and 2012 were probably less joined up, more heterogeneous, and, perhaps, even, smaller, than similar phenomena during the last decade, but what was striking was their 'resonance' among mainstream public opinion-the 'bubbling up' of subterranean politics. The main findings included: • Subterranean political actors perceive the crisis as a political crisis rather than a reaction to austerity. Subterranean politics is just as much a characteristic of Germany, where there are no austerity policies, as other countries. • Subterranean political actors are concerned about democracy but not as it is currently practised. They experiment with new democratic practises, in the squares, on the Internet, and elsewhere. • This new political generation not only uses social networking to organize but the Internet has profoundly affected the culture of political activism. • In contrast to mainstream public debates, Europe is 'invisible' even though many subterranean political actors feel themselves to be European. The research concludes that the term 'subterranean politics' is a useful concept that needs further investigation and that Europe needs to be problematized to seek a way out of the crisis

Antibodies protect against intracellular bacteria by Fc receptor-mediated lysosomal targeting

The protective effect of antibodies (Abs) is generally attributed to neutralization or complement activation. Using Legionella pneumophila and Mycobacterium bovis bacillus Calmette–Guérin as a model, we discovered an additional mechanism of Ab-mediated protection effective against intracellular pathogens that normally evade lysosomal fusion. We show that Fc receptor (FcR) engagement by Abs, which can be temporally and spatially separated from bacterial infection, renders the host cell nonpermissive for bacterial replication and targets the pathogens to lysosomes. This process is strictly dependent on kinases involved in FcR signaling but not on host cell protein synthesis or protease activation. Based on these findings, we propose a mechanism whereby Abs and FcR engagement subverts the strategies by which intracellular bacterial pathogens evade lysosomal degradation