In Situ Characterization of Splenic Brucella melitensis Reservoir Cells during the Chronic Phase of Infection in Susceptible Mice

Brucella are facultative intracellular Gram-negative coccobacilli that chronically infect humans as well as domestic and wild-type mammals, and cause brucellosis. Alternatively activated macrophages (M2a) induced by IL-4/IL-13 via STAT6 signaling pathways have been frequently described as a favorable niche for long-term persistence of intracellular pathogens. Based on the observation that M2a-like macrophages are induced in the spleen during the chronic phase of B. abortus infection in mice and are strongly infected in vitro, it has been suggested that M2a macrophages could be a potential in vivo niche for Brucella. In order to test this hypothesis, we used a model in which infected cells can be observed directly in situ and where the differentiation of M2a macrophages is favored by the absence of an IL-12-dependent Th1 response. We performed an in situ analysis by fluorescent microscopy of the phenotype of B. melitensis infected spleen cells from intranasally infected IL-12p40^-/- BALB/c mice and the impact of STAT6 deficiency on this phenotype. Most of the infected spleen cells contained high levels of lipids and expressed CD11c and CD205 dendritic cell markers and Arginase1, but were negative for the M2a markers Fizz1 or CD301. Furthermore, STAT6 deficiency had no effect on bacterial growth or the reservoir cell phenotype in vivo, leading us to conclude that, in our model, the infected cells were not Th2-induced M2a macrophages. This characterization of B. melitensis reservoir cells could provide a better understanding of Brucella persistence in the host and lead to the design of more efficient therapeutic strategies.     

Healthcare-Related Regret among Nurses and Physicians Is Associated with Self-Rated Insomnia Severity: A Cross-Sectional Study

To examine the association between healthcare-related regrets and sleep difficulties among nurses and physicians, we surveyed 240 nurses and 220 physicians at the University Hospitals of Geneva. Regret intensity and regret coping were measured using validated scales. Sleep difficulties were measured using the Insomnia Severity Index (ISI), and an additional question assessed the frequency of sleeping pill use. After controlling for sex, profession, years of experience, rate of employment, and depression as well as for all other regret-related variables, the following variables remained significantly associated with self-rated severity of insomnia: regret intensity (slope = 1.32, p = 0.007, 95%CI: [0.36; 2.29], std. coefficient = 0.16) and maladaptive (e.g., rumination) emotion-focused coping (slope = 1.57, p = 0.002, 95%CI: [0.60; 2.55], std. coefficient = 0.17) remained significant predictors of self-rated insomnia severity. If these cross-sectional associations represent causal effects, the development of regret-management programs may represent a promising approach to mitigating sleep difficulties of healthcare professionals.     

Bacterial community changes during bioremediation of aliphatic hydrocarbon-contaminated soil

The microbial community response during the oxygen biostimulation process of aged oil-polluted soils is poorly documented and there is no reference for the long-term monitoring of the unsaturated zone. To assess the potential effect of air supply on hydrocarbon fate and microbial community structure, two treatments (0 and 0.056 mol h?1 molar flow rate of oxygen) were performed in fixed bed reactors containing oil-polluted soil. Microbial activity was monitored continuously over 2 years throughout the oxygen biostimulation process. Microbial community structure before and after treatment for 12 and 24 months was determined using a dual rRNA/rRNA gene approach, allowing us to characterize bacteria that were presumably metabolically active and therefore responsible for the functionality of the community in this polluted soil. Clone library analysis revealed that the microbial community contained many rare phylotypes. These have never been observed in other studied ecosystems. The bacterial community shifted from Gammaproteobacteria to Actinobacteria during the treatment. Without aeration, the samples were dominated by a phylotype linked to the Streptomyces. Members belonging to eight dominant phylotypes were well adapted to the aeration process. Aeration stimulated an Actinobacteria phylotype that might be involved in restoring the ecosystem studied. Phylogenetic analyses suggested that this phylotype is a novel, deep-branching member of the Actinobacteria related to the well-studied genus Acidimicrobium.     

Chain and conformation stability of solid-state DNA: implications for room temperature storage

There is currently wide interest in room temperature storage of dehydrated DNA. However, there is insufficient knowledge about its chemical and structural stability. Here, we show that solid-state DNA degradation is greatly affected by atmospheric water and oxygen at room temperature. In these conditions DNA can even be lost by aggregation. These are major concerns since laboratory plastic ware is not airtight. Chain-breaking rates measured between 70°C and 140°C seemed to follow Arrhenius’ law. Extrapolation to 25°C gave a degradation rate of about 1–40 cuts/10⁵ nucleotides/century. However, these figures are to be taken as very tentative since they depend on the validity of the extrapolation and the positive or negative effect of contaminants, buffers or additives. Regarding the secondary structure, denaturation experiments showed that DNA secondary structure could be preserved or fully restored upon rehydration, except possibly for small fragments. Indeed, below about 500 bp, DNA fragments underwent a very slow evolution (almost suppressed in the presence of trehalose) which could end in an irreversible denaturation. Thus, this work validates using room temperature for storage of DNA if completely protected from water and oxygen.     

RRP1B targets PP1 to mammalian cell nucleoli and is associated with Pre-60S ribosomal subunits

A pool of protein phosphatase 1 (PP1) accumulates within nucleoli and accounts for a large fraction of the serine/threonine protein phosphatase activity in this subnuclear structure. Using a combination of fluorescence imaging with quantitative proteomics, we mapped the subnuclear localization of the three mammalian PP1 isoforms stably expressed as GFP-fusions in live cells and identified RRP1B as a novel nucleolar targeting subunit that shows a specificity for PP1β and PP1γ. RRP1B, one of two mammalian orthologues of the yeast Rrp1p protein, shows an RNAse-dependent localization to the granular component of the nucleolus and distributes in a similar manner throughout the cell cycle to proteins involved in later steps of rRNA processing. Quantitative proteomic analysis of complexes containing both RRP1B and PP1γ revealed enrichment of an overlapping subset of large (60S) ribosomal subunit proteins and pre-60S nonribosomal proteins involved in mid-late processing. Targeting of PP1 to this complex by RRP1B in mammalian cells is likely to contribute to modulation of ribosome biogenesis by mechanisms involving reversible phosphorylation events, thus playing a role in the rapid transduction of cellular signals that call for regulation of ribosome production in response to cellular stress and/or changes in growth conditions.     

Discovery of a novel series of potent S1P1 agonists

The discovery of a novel series of S1P1 agonists is described. Starting from a micromolar HTS positive, iterative optimization gave rise to several single-digit nanomolar S1P1 agonists. The compounds were able to induce internalization of the S1P1 receptor, and a selected compound was shown to be able to induce lymphopenia in mice after oral dosing.     

Potential impact of wind farms on territories of large eagles in southeastern Spain

Although wind farms in Spain have increased in numbers in recent years, their impact on birds, particularly large raptors, has received relatively little attention in the scientific literature. We study the potential impact of 72 wind energy developments planned for the south-east of Spain covering 128 golden eagle and 152 Bonelli’s eagle territories using nearest neighbour distances (NND) as an indicator of potential future interactions (abandonment, displacement and collision risk). Our analyses indicate low levels of potential interactions between wind farms and large eagles, and suggest that, of the two species studied, golden eagles will be the more affected because a greater proportion of wind farms will be constructed close to the breeding territories of this species. In the light of these findings, we discuss various management strategies in order to improve the compatibility of harvesting wind energy with the conservation of both species.