Diversity links to functionality: Unraveling the impact of pressure disruption and culture medium on crude oil-enriched microbial communities from the deep Eastern Mediterranean Sea

Mesopelagic water from the deep Eastern Mediterranean Sea (EMS) was collected under disrupted (REPRESS) or undisturbed (HP) pressure conditions and was acclimated to oil (OIL) or dispersed-oil (DISPOIL) under in situ pressure and temperature (10 MPa, 14 °C). Decompression resulted in oil-acclimatised microbial communities of lower diversity despite the restoration of in situ pressure conditions during the 1-week incubation. Further biodiversity loss was observed when oil-acclimatised communities were transferred to ONR7 medium to facilitate the isolation of oil-degrading bacteria. Microbial diversity loss impacted the degradation of recalcitrant oil compounds, especially PAHs, as low-abundance taxa, linked with PAH degradation, were outcompeted in the enrichment process. Thalassomonas, Pseudoalteromonas, Halomonas and Alcanivorax were enriched in ONR7 under all experimental conditions. No effect of dispersant application on the microbial community structure was identified. A. venustensis was isolated under all tested conditions suggesting a potential key role of this species in hydrocarbons removal in the deep EMS.

Toward the Separation of Different Heating Mechanisms in Magnetic Particle Hyperthermia

Magnetic particle hyperthermia (MPH) is a promising method for cancer treatment using magnetic nanoparticles (MNPs), which are subjected to an alternating magnetic field for local heating to the therapeutic range of 41-45 °C. In this window, the malignant regions (i.e., cancer cells) undergo a severe thermal shock while healthy tissues sustain this thermal regime with significantly milder side effects. Since the heating efficiency is directly associated with nanoparticle size, MNPs should acquire the appropriate size to maximize heating together with minimum toxicity. Herein, we report on facile synthetic controls to synthesize MNPs by an aqueous precipitation method, whereby tuning the pH values of the solution (9.0-13.5) results in a wide range of average MNP diameters from 16 to 76 nm. With respect to their size, the structural and magnetic properties of the MNPs are evaluated by adjusting the most important parameters, i.e. the MNP surrounding medium (water/agarose), the MNP concentration (1-4 mg mL^-1), and the field amplitude (20-50 mT) and frequency (103, 375, 765 kHz). Consequently, the maximum heating efficiency is determined for each MNP size and set of parameters, outlining the optimum MNPs for MPH treatment. In this way, we can address the different heat generation mechanisms (Brownian, Néel, and hysteresis losses) to different sizes and separate Brownian and hysteresis losses for optimized sizes by studying the heat generation as a function of the medium viscosity. Finally, MNPs immobilized into agarose solution are studied under low-field MPH treatment to find the optimum conditions for clinical applications.

P4392A systematic review and meta-analysis of the cardiovascular effects of e-cigarette

Background

Electronic cigarette (EC) is marketed as a safe alternative to tobacco smoking, but EC cardiovascular effects remains largely unknown.

Purpose

To systematically review and meta-analyse published literature to investigate the cardiovascular effects and associated risk from EC use.

Methods

We searched PubMed from January 2000 until November 2017 for published studies assessing the cardiovascular effects of EC. For each eligible study we used the mean difference (MD) with 95% confidence intervals (CIs) for SBP, DBP and HR. The pooled MDs for each outcome of interest were calculated by using a fixed effects model. The presence of heterogeneity among studies was evaluated by the I2 statistic.

Results

We report conflicting evidence on the effects of EC on heart rate and blood pressure, which is mainly based on non-randomized clinical studies of moderate quality. In a meta-analysis of 14 studies (n=441 participants), that despite the negative effects of EC on heart rate (pooled MD=2.27, 95% CI: 1.64 to 2.89, p<0.001), diastolic (DBP, pooled MD=2.01mmHg, 95% CI: 0.62 to 3.39, p=0.004) and systolic blood pressure (SBP, pooled MD=2.02mmHg, 95% CI: 0.07 to 3.97, p=0.042), benefits may be observed in terms of blood pressure regulation when switching from tobacco smoking to EC (SBP pooled MD=−7.00, 95% CI: −9.63 to −4.37, p<0.001; DBP pooled MD=−3.65, 95% CI: −5.71 to −1.59, p=0.001). Evidence suggests that EC negatively affects endothelial function, arterial stiffness and the long-term risk for coronary events, but these findings are derived from single study reports and have not been confirmed in additional studies.

Conclusions

We report adverse effects of EC use on heart rate and blood pressure. Unless supported by stronger evidence, EC should not be labelled as cardiovascular safe products. Future studies should delineate whether EC use is less hazardous to cardiovascular health than conventional cigarette smoking.

Unconventional Targeting of a Thiol Peroxidase to the Mitochondrial Intermembrane Space Facilitates Oxidative Protein Folding

Thiol peroxidases are conserved hydrogen peroxide scavenging and signaling molecules that contain redox-active cysteine residues. We show here that Gpx3, the major H₂O₂ sensor in yeast, is present in the mitochondrial intermembrane space (IMS), where it serves a compartment-specific role in oxidative metabolism. The IMS-localized Gpx3 contains an 18-amino acid N-terminally extended form encoded from a non-AUG codon. This acts as a mitochondrial targeting signal in a pathway independent of the hitherto known IMS-import pathways. Mitochondrial Gpx3 interacts with the Mia40 oxidoreductase in a redox-dependent manner and promotes efficient Mia40-dependent oxidative protein folding. We show that cells lacking Gpx3 have aberrant mitochondrial morphology, defective protein import capacity, and lower inner membrane potential, all of which can be rescued by expression of a mitochondrial-only form of Gpx3. Together, our data reveal a novel role for Gpx3 in mitochondrial redox regulation and protein homeostasis.

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A pool of yeast Gpx3 localizes to mitochondria via translation from a non-AUG codon

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Loss of Gpx3 causes defects in mitochondrial architecture and membrane potential

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Gpx3 interacts with the oxidative protein folding machinery in the IMS