Cutting edge: cyclic polypeptide and aminoglycoside antibiotics trigger IL-1β secretion by activating the NLRP3 inflammasome.

Clinical use of antibiotics is based on their capacity to inhibit bacterial growth via bacteriostatic or bacteriocidal effects. In this article, we show that the aminoglycoside antibiotic neomycin, the cyclic lipopeptide antibiotic polymyxin B, and the cyclic peptide antibiotics gramicidin and tyrothricin can induce IL-1β secretion in bone marrow dendritic cells and macrophages. LPS priming was required to trigger the transcription and translation of pro-IL-1β but was independent of TNFR or IL-1R signaling. All four antibiotics required the NLRP3 inflammasome, the adaptor ASC, and caspase-1 activation to secrete IL-1β, a process that depended on potassium efflux but was independent of P2X7 receptor. All four antibiotics induced neutrophil influx into the peritoneal cavity of mice, which required NLRP3 only in the case of polymyxin B. Together, certain antibiotics have the potential to directly activate innate immunity of the host.

Diagnostic Performances of 18F-FDG Positron Emission Tomography in Large Vessels Vasculitis: Meta-analysis

Toperform a meta-analysis of FDG-PET performances in the diagnosis of largevessels vasculitis (Giant Cell Arteritis (GCA) associated or not withPolymyalgia Rheumatica(PMR), Takayasu). Materials and methods : The MEDLINE,Cochrane Library, Embase were searched for relevant original articlesdescribing FDG-PET for vasculitis assessment, using MesH terms ("GiantCell Arteritis or Vasculitis" AND "PET"). Criteria for inclusionwere:(1)FDG-PET for diagnosis of vasculitis(2)American College of Rheumatologycriteria as reference standard(3)control group. After data extraction, analyseswere performed using a random-effects model. Results : Of 184 citations(database search and references screening),70 articles were reviewed of which12 eligible studies were extracted (sensitivity range from 32% to 97%). 7studies fulfilled all inclusion criteria. Owing to overlapping population, 1study was excluded. Statistical heterogeneity justified the random-effectsmodel. Pooled 6 studies analysis(116 vasculitis,224 controls) showed a 81%sensitivity (95%CI:70-89%);a 89% specificity (95%CI:77-95%);a 85%PPV(95%CI:63-95%); a 90% NPV(95%CI:79-95%);a 7.1 positive LR(95%CI:3.4-14.9); a0.2 negative LR(95%CI:0.14-0.35) and 90.1 DOR(95%CI: 18.6-437). Conclusion :FDG-PET has good diagnostic performances in the detection of large vesselsvasculitis. Its promising role could be extended to follow up patients undertreatment, but further studies are needed to confirm this possibility.

Phytochrome interacting factors 4 and 5 redundantly limit seedling de-etiolation in continuous far-red light.

Phytochromes are red/far-red photosensors that regulate numerous developmental programs in plants. Among them, phytochrome A (phyA) is essential to enable seedling de-etiolation under continuous far-red (FR) light, a condition that mimics the environment under a dense canopy. The ecological relevance of this response is demonstrated by the high mortality rate of phyA mutant plants that germinate in deep vegetational shade. phyA signaling involves direct interaction of the photoreceptor with phytochrome-interacting factors PIF1 and PIF3, members of the bHLH transcription factor family. Here we investigated the involvement of PIF4 and PIF5 in phyA signaling, and found that they redundantly control de-etiolation in FR light. The pif4 pif5 double mutant is hypersensitive to low fluence rates of FR light. This phenotype is dependent on FR light perception by phyA, but does not rely on alterations in the phyA level. Our microarray analysis shows that PIF4 and PIF5 are part of an inhibitory mechanism that represses the expression of some light-responsive genes in the dark, and that they are also needed for full expression of several growth-related genes in the light. Unlike PIF1 and PIF3, PIF4 and PIF5 are not degraded in response to FR light, indicating that they are light-regulated by a different mechanism. Our genetic analysis suggests that this is achieved through sequestration of these PIFs by the closely related bHLH transcription factor HFR1 (long hypocotyl in FR light).

Enhanced EGFP Fluorescence Emission in Presence of PEG Aqueous Solutions and PIB1000-PEG6000-PIB1000 Copolymer Vesicles.

An EGFP construct interacting with the PIB1000-PEG6000-PIB1000 vesicles surface reported a ~2-fold fluorescence emission enhancement. Because of the constructs nature with the amphiphilic peptide inserted into the PIB core, EGFP is expected to experience a "pure" PEG environment. To unravel this phenomenon PEG/water solutions at different molecular weights and concentrations were used. Already at ~1 : 10 protein/PEG molar ratio the increase in fluorescence emission is observed reaching a plateau correlating with the PEG molecular weight. Parallel experiments in presence of glycerol aqueous solutions did show a slight fluorescence enhancement however starting at much higher concentrations. Molecular dynamics simulations of EGFP in neat water, glycerol, and PEG aqueous solutions were performed showing that PEG molecules tend to "wrap" the protein creating a microenvironment where the local PEG concentration is higher compared to its bulk concentration. Because the fluorescent emission can be perturbed by the refractive index surrounding the protein, the clustering of PEG molecules induces an enhanced fluorescence emission already at extremely low concentrations. These findings can be important when related to the use of EGFP as reported in molecular biology experiments.

Resigned but satisfied: The negative impact of public service motivation and red tape on work satisfaction

This article examines the relationship between red tape, Public Service Motivation (PSM) and a particular work outcome labelled 'resigned satisfaction'. Using data from a national survey of over 3754 public servants working at the municipal level in Switzerland, this study shows the importance of looking more closely at the concept of work satisfaction and, furthermore, of thoroughly investigating the impact of the different PSM dimensions on work outcomes. Unsurprisingly, research findings show that red tape is the most important predictor of resignation. Nevertheless, when PSM dimensions are analysed separately, results demonstrate that 'commitment to public interest/civic duty' and, to a lesser extent, 'attraction to policy-making' decrease resignation, whereas 'compassion' and 'self-sacrifice' increase it. This study thus highlights some of the negative (or undesirable) effects of PSM that have not been previously addressed in PSM literature.

Cutting edge: thymic crosstalk regulates delta-like 4 expression on cortical epithelial cells.

Interactions between Notch1 receptors on lymphoid progenitors and Delta-like 4 (DL4) ligands on cortical thymic epithelial cells (cTEC) are essential for T cell lineage commitment, expansion, and maturation in the thymus. Using a novel mAb against DL4, we show that DL4 levels on cTEC are very high in the fetal and neonatal thymus when thymocyte expansion is maximal but decrease dramatically in the adult when steady-state homeostasis is attained. Analysis of mutant mouse strains where thymocyte development is blocked at different stages indicates that lymphostromal interactions ("thymus crosstalk") are required for DL4 down-regulation on cTEC. Reconstitution of thymocyte development in these mutant mice further suggests that maturation of thymocytes to the CD4(+)CD8(+) stage and concomitant expansion are needed to promote DL4 down-regulation on cTEC. Collectively, our data support a model where thymic crosstalk quantitatively regulates the rate of Notch1-dependent thymopoiesis by controlling DL4 expression levels on cTEC.

The red island and the seven dwarfs: body size reduction in Cheirogaleidae

AimSmall body size in Madagascar's dwarf and mouse lemurs (Cheirogaleidae) is generally viewed as primitive. We investigated the evolution of body size in this family and in its sister-taxon, the Lepilemuridae, from phylogenetic, ontogenetic and adaptive perspectives. LocationMadagascar. MethodsWe used a phylogenetic method to reconstruct the evolution of body size in lemurs, and allometric regression models of gestation periods and static and growth allometries in Cheirogaleidae and Lepilemuridae to test the hypothesis that dwarfing occurred as a result of truncated ontogeny (progenesis). We also examined adaptive hypotheses relating body size to environmental variability, life history, seasonality of reproduction, hypothermy (use of torpor), and a diet rich in plant exudates. ResultsOur results indicated that cheirogaleids experienced at least four independent events of body size reduction from an ancestor as large as living Lepilemuridae, by means of progenesis. Our interpretation is supported by the paedomorphic appearance and parallel ontogenetic trajectories of the dwarf taxa, as well as their very short gestation periods and increased fecundity. Lepilemur species that occupy more predictable environments are significantly larger than those occupying unpredictable habitats. Main conclusionsCheirogaleidae appear to be paedomorphic dwarfs, a consequence of progenesis, probably as an adaptation to high environmental unpredictability. Although the capacity to use hypothermy is related to small body size, this advantage is unlikely to have driven dwarfing in cheirogaleids. We propose that gummmivory/exudativory co-evolved with body size reduction in this clade, probably from a folivorous ancestor. Their small size is derived, and their suitability as models for the ancestral primate' is therefore dubious.

Cutting edge: a novel viral TNF receptor superfamily member in virulent strains of human cytomegalovirus.

The UL144 open reading frame found in clinical isolates of human CMV (HCMV) encodes a structural homologue of the herpesvirus entry mediator, a member of the TNFR superfamily. UL144 is a type I transmembrane glycoprotein that is expressed early after infection of fibroblasts; however, it is retained intracellularly. A YXXZ motif in the highly conserved cytoplasmic tail contributes to UL144 subcellular distribution. The finding that no known ligand of the TNF family binds UL144 suggests that its mechanism of action is distinct from other known viral immune evasion genes. Specific Abs to UL144 can be detected in the serum of a subset of HCMV seropositive individuals infected with HIV. This work establishes a novel molecular link between the TNF superfamily and herpesvirus that may contribute to the ability of HCMV to escape immune clearance.

Increase of [(18)F]FLT Tumor Uptake In Vivo Mediated by FdUrd: Toward Improving Cell Proliferation Positron Emission Tomography.

PURPOSE: 3'-deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT), a cell proliferation positron emission tomography (PET) tracer, has been shown in numerous tumors to be more specific than 2-deoxy-2-[(18)F]fluoro-D: -glucose ([(18)F]FDG) but less sensitive. We studied the capacity of a nontoxic concentration of 5-fluoro-2'-deoxyuridine (FdUrd), a thymidine synthesis inhibitor, to increase uptake of [(18)F]FLT in tumor xenografts. METHODS: The duration of the FdUrd effect in vivo on tumor cell cycling and thymidine analogue uptake was studied by varying FdUrd pretreatment timing and holding constant the timing of subsequent flow cytometry and 5-[(125)I]iodo-2'-deoxyuridine biodistribution measurements. In [(18)F]FLT studies, FdUrd pretreatment was generally performed 1 h before radiotracer injection. [(18)F]FLT biodistributions were measured 1 to 3 h after radiotracer injection of mice grafted with five different human tumors and pretreated or not with FdUrd and compared with [(18)F]FDG tumor uptake. Using microPET, the dynamic distribution of [(18)F]FLT was followed for 1.5 h in FdUrd pretreated mice. High-field T2-weighted magnetic resonance imaging (MRI) and histology were used comparatively in assessing tumor viability and proliferation. RESULTS: FdUrd induced an immediate increase in tumor uptake of 5-[(125)I]iodo-2'-deoxyuridine, that vanished after 6 h, as also confirmed by flow cytometry. Biodistribution measurements showed that FdUrd pretreatment increased [(18)F]FLT uptake in all tumors by factors of 3.2 to 7.8 compared with controls, while [(18)F]FDG tumor uptake was about fourfold and sixfold lower in breast cancers and lymphoma. Dynamic PET in FdUrd pretreated mice showed that [(18)F]FLT uptake in all tumors increased steadily up to 1.5 h. MRI showed a well-vascularized homogenous lymphoma with high [(18)F]FLT uptake, while in breast cancer, a central necrosis shown by MRI was inactive in PET, consistent with the histomorphological analysis. CONCLUSION: We showed a reliable and significant uptake increase of [(18)F]FLT in different tumor xenografts after low-dose FdUrd pretreatment. These results show promise for a clinical application of FdUrd aimed at increasing the sensitivity of [(18)F]FLT PET.

MR-IMPACT II: Magnetic Resonance Imaging for Myocardial Perfusion Assessment in Coronary artery disease Trial: perfusion-cardiac magnetic resonance vs. single-photon emission computed tomography for the detection of coronary artery disease: a comparative multicentre, multivendor trial.

Aims Perfusion-cardiac magnetic resonance (CMR) has emerged as a potential alternative to single-photon emission computed tomography (SPECT) to assess myocardial ischaemia non-invasively. The goal was to compare the diagnostic performance of perfusion-CMR and SPECT for the detection of coronary artery disease (CAD) using conventional X-ray coronary angiography (CXA) as the reference standard. Methods and results In this multivendor trial, 533 patients, eligible for CXA or SPECT, were enrolled in 33 centres (USA and Europe) with 515 patients receiving MR contrast medium. Single-photon emission computed tomography and CXA were performed within 4 weeks before or after CMR in all patients. The prevalence of CAD in the sample was 49%. Drop-out rates for CMR and SPECT were 5.6 and 3.7%, respectively (P = 0.21). The primary endpoint was non-inferiority of CMR vs. SPECT for both sensitivity and specificity for the detection of CAD. Readers were blinded vs. clinical data, CXA, and imaging results. As a secondary endpoint, the safety profile of the CMR examination was evaluated. For CMR and SPECT, the sensitivity scores were 0.67 and 0.59, respectively, with the lower confidence level for the difference of +0.02, indicating superiority of CMR over SPECT. The specificity scores for CMR and SPECT were 0.61 and 0.72, respectively (lower confidence level for the difference: -0.17), indicating inferiority of CMR vs. SPECT. No severe adverse events occurred in the 515 patients. Conclusion In this large multicentre, multivendor study, the sensitivity of perfusion-CMR to detect CAD was superior to SPECT, while its specificity was inferior to SPECT. Cardiac magnetic resonance is a safe alternative to SPECT to detect perfusion deficits in CAD.

Added prognostic value of myocardial blood flow quantitation in rubidium-82 positron emission tomography imaging.

AIMS: We studied the respective added value of the quantitative myocardial blood flow (MBF) and the myocardial flow reserve (MFR) as assessed with (82)Rb positron emission tomography (PET)/CT in predicting major adverse cardiovascular events (MACEs) in patients with suspected myocardial ischaemia. METHODS AND RESULTS: Myocardial perfusion images were analysed semi-quantitatively (SDS, summed difference score) and quantitatively (MBF, MFR) in 351 patients. Follow-up was completed in 335 patients and annualized MACE (cardiac death, myocardial infarction, revascularization, or hospitalization for congestive heart failure or de novo stable angor) rates were analysed with the Kaplan-Meier method in 318 patients after excluding 17 patients with early revascularizations (<60 days). Independent predictors of MACEs were identified by multivariate analysis. During a median follow-up of 624 days (inter-quartile range 540-697), 35 MACEs occurred. An annualized MACE rate was higher in patients with ischaemia (SDS >2) (n = 105) than those without [14% (95% CI = 9.1-22%) vs. 4.5% (2.7-7.4%), P < 0.0001]. The lowest MFR tertile group (MFR <1.8) had the highest MACE rate [16% (11-25%) vs. 2.9% (1.2-7.0%) and 4.3% (2.1-9.0%), P < 0.0001]. Similarly, the lowest stress MBF tertile group (MBF <1.8 mL/min/g) had the highest MACE rate [14% (9.2-22%) vs. 7.3% (4.2-13%) and 1.8% (0.6-5.5%), P = 0.0005]. Quantitation with stress MBF or MFR had a significant independent prognostic power in addition to semi-quantitative findings. The largest added value was conferred by combining stress MBF to SDS. This holds true even for patients without ischaemia. CONCLUSION: Perfusion findings in (82)Rb PET/CT are strong MACE outcome predictors. MBF quantification has an added value allowing further risk stratification in patients with normal and abnormal perfusion images.

Detection of colorectal carcinoma by emission-computerized tomography after injection of 123I-labeled Fab or F(ab')2 fragments from monoclonal anti-carcinoembryonic antigen antibodies.

This clinical study was based on experimental results obtained in nude mice grafted with human colon carcinoma, showing that injected 131I-labeled F(ab')2 and Fab fragments from high affinity anti-carcinoembryonic antigen (CEA) monoclonal antibodies (MAb) gave markedly higher ratios of tumor to normal tissue localization than intact MAb. 31 patients with known colorectal carcinoma, including 10 primary tumors, 13 local tumor recurrences, and 21 metastatic involvements, were injected with 123I-labeled F(ab')2 (n = 14) or Fab (n = 17) fragments from MAb anti-CEA. The patients were examined by emission-computerized tomography (ECT) at 6, 24, and sometimes 48 h after injection using a rotating dual head scintillation camera. All 23 primary tumors and local recurrences except one were clearly visualized on at least two sections of different tomographic planes. Interestingly, nine of these patients had almost normal circulating CEA levels, and three of the visualized tumors weighed only 3-5 g. Among 19 known metastatic tumor involvements, 14 were correctly localized by ECT. Two additional liver and several bone metastases were discovered by immunoscintigraphy. Altogether, 86% of the tumor sites were detected, 82% with F(ab')2 and 89% with Fab fragments. The contrast of the tumor images obtained with Fab fragments suggests that this improved method of immunoscintigraphy has the potential to detect early tumor recurrences and thus to increase the survival of patients. The results of this retrospective study, however, should be confirmed in a prospective study before this method can be recommended for the routine diagnosis of cancer.

Diagnostic performance of Fluorine-18-Fluorodeoxyglucose positron emission tomography in the assessment of pleural abnormalities in cancer patients: A systematic review and a meta-analysis.

OBJECTIVE: To systematically review and meta-analyze published data about the diagnostic performance of Fluorine-18-Fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and PET/computed tomography (PET/CT) in the assessment of pleural abnormalities in cancer patients. METHODS: A comprehensive literature search of studies published through June 2013 regarding the role of (18)F-FDG-PET and PET/CT in evaluating pleural abnormalities in cancer patients was performed. All retrieved studies were reviewed and qualitatively analyzed. Pooled sensitivity, specificity, positive and negative likelihood ratio (LR+ and LR-) and diagnostic odd ratio (DOR) of (18)F-FDG-PET or PET/CT on a per patient-based analysis were calculated. The area under the summary ROC curve (AUC) was calculated to measure the accuracy of these methods in the assessment of pleural abnormalities. Sub-analyses considering (18)F-FDG-PET/CT and patients with lung cancer only were carried out. RESULTS: Eight studies comprising 360 cancer patients (323 with lung cancer) were included. The meta-analysis of these selected studies provided the following results: sensitivity 86% [95% confidence interval (95%CI): 80-91%], specificity 80% [95%CI: 73-85%], LR+ 3.7 [95%CI: 2.8-4.9], LR- 0.18 [95%CI: 0.09-0.34], DOR 27 [95%CI: 13-56]. The AUC was 0.907. No significant improvement considering PET/CT studies only and patients with lung cancer was found. CONCLUSIONS: (18)F-FDG-PET and PET/CT demonstrated to be useful diagnostic imaging methods in the assessment of pleural abnormalities in cancer patients, nevertheless possible sources of false-negative and false-positive results should be kept in mind. The literature focusing on the use of (18)F-FDG-PET and PET/CT in this setting remains still limited and prospective studies are needed.

Characterizing emission and breathing-zone concentrations following exposure cases to fluororesin-based waterproofing spray mists.

Measurements and simulations were performed to assess workers' exposure to solvent vapors and aerosols during the waterproofing of a tiled surface. This investigation followed two recent incidents in the same company where workers experienced acute respiratory illness after spraying a stain-repellent resin containing fluorinated polymers on stone-tiled walls and floors. Because the waterproofing activity had been done for years at the tile company without encountering any exposure problems prior to these cases, it was strongly suspected that the incidents were linked to a recent change in the composition of the coating mixture. Experimental measurements and simulations indicated that the emission rate of particles smaller than 10 microm may be estimated at 0.66 mg/sec (SD 0.10) for the old resin and at 0.37 mg/sec (SD 0.04) for the new one. The measurement of the solvent emission rate from surfaces coated with the two resins indicated that shortly after spraying, the emission was in the range of 18 to 20 mg/sec x m2 and was similar for both products. Solvent and overspray emission rates were introduced in a two-zone compartment model. The results obtained in the near-field indicate significant exposure to overspray mist (7 and 34 mg/m3 for new resin) and solvent vapors (80 to 350 ppm for the new resin). It was also shown that the introduction of the new resin tended to significantly decrease the levels of solvents and particulates in the workers' breathing zone. These results strongly suggest that cases of acute respiratory illness are related to the specific toxicity of the fluorinated polymer itself. The fact that the same polymer is used in various commercial products raises concern regarding other possible occupational and domestic exposures.