Functional connectivity of EEG is subject-specific, associated with phenotype, and different from fMRI

A variety of psychiatric, behavioral and cognitive phenotypes have been linked to brain ‘’functional connectivity’’ -- the pattern of correlation observed between different brain regions. Most commonly assessed using functional magnetic resonance imaging (fMRI), here, we investigate the connectivity-phenotype associations with functional connectivity measured with electroencephalography (EEG), using phase-coupling. We analyzed data from the publicly available Healthy Brain Network Biobank. This database compiles a growing sample of children and adolescents, currently encompassing 1657 individuals. Among a variety of assessment instruments we focus on ten phenotypic and additional demographic measures that capture most of the variance in this sample. The largest effect sizes are found for age and sex for both fMRI and EEG. We replicate previous findings of an association of Intelligence Quotient (IQ) and Attention Deficit Hyperactivity Disorder (ADHD) with the pattern of fMRI functional connectivity. We also find an association with socioeconomic status, anxiety and the Child Behavior Checklist Score. For EEG we find a significant connectivity-phenotype relationship with IQ. The actual spatial patterns of functional connectivity are quite different between fMRI and source-space EEG. However, within EEG we observe clusters of functional connectivity that are consistent across frequency bands. Additionally we analyzed reproducibility of functional connectivity. We compare connectivity obtained with different tasks, including resting state, a video and a visual flicker task. For both EEG and fMRI the variation between tasks was smaller than the variability observed between subjects. We also found an increase of reliability with increasing frequency of the EEG, and increased sampling duration. We conclude that, while the patterns of functional connectivity are distinct between fMRI and phase-coupling of EEG, they are nonetheless similar in their robustness to the task, and similar in that idiosyncratic patterns of connectivity predict individual phenotypes

The dynamic architecture of the metabolic switch in Streptomyces coelicolor

[EN] Background: During the lifetime of a fermenter culture, the soil bacterium S. coelicolor undergoes a major metabolic switch from exponential growth to antibiotic production. We have studied gene expression patterns during this switch, using a specifically designed Affymetrix genechip and a high-resolution time-series of fermenter-grown samples.Results: Surprisingly, we find that the metabolic switch actually consists of multiple finely orchestrated switching events. Strongly coherent clusters of genes show drastic changes in gene expression already many hours before the classically defined transition phase where the switch from primary to secondary metabolism was expected. The main switch in gene expression takes only 2 hours, and changes in antibiotic biosynthesis genes are delayed relative to the metabolic rearrangements. Furthermore, global variation in morphogenesis genes indicates an involvement of cell differentiation pathways in the decision phase leading up to the commitment to antibiotic biosynthesis.Conclusions: Our study provides the first detailed insights into the complex sequence of early regulatory events during and preceding the major metabolic switch in S. coelicolor, which will form the starting point for future attempts at engineering antibiotic production in a biotechnological settingSIWe are very grateful to Mervyn Bibb for his generous support with the Affymetrix custom microarray design. We acknowledge the excellent technical help of K. Klein, S. Poths, M. Walter, A. Øverby and E. Hansen. This project was supported by grants of the ERA-NET SySMO Project [GEN2006-27745-E/SYS]: (P-UK-01-11-3i) and the Research Council of Norway [project no. 181840/I30

Large-scale mapping of mutations affecting zebrafish development

BACKGROUND: Large-scale mutagenesis screens in the zebrafish employing the mutagen ENU have isolated several hundred mutant loci that represent putative developmental control genes. In order to realize the potential of such screens, systematic genetic mapping of the mutations is necessary. Here we report on a large-scale effort to map the mutations generated in mutagenesis screening at the Max Planck Institute for Developmental Biology by genome scanning with microsatellite markers. RESULTS: We have selected a set of microsatellite markers and developed methods and scoring criteria suitable for efficient, high-throughput genome scanning. We have used these methods to successfully obtain a rough map position for 319 mutant loci from the Tübingen I mutagenesis screen and subsequent screening of the mutant collection. For 277 of these the corresponding gene is not yet identified. Mapping was successful for 80 % of the tested loci. By comparing 21 mutation and gene positions of cloned mutations we have validated the correctness of our linkage group assignments and estimated the standard error of our map positions to be approximately 6 cM. CONCLUSION: By obtaining rough map positions for over 300 zebrafish loci with developmental phenotypes, we have generated a dataset that will be useful not only for cloning of the affected genes, but also to suggest allelism of mutations with similar phenotypes that will be identified in future screens. Furthermore this work validates the usefulness of our methodology for rapid, systematic and inexpensive microsatellite mapping of zebrafish mutations

Low-flow CO2 removal in combination with renal replacement therapy effectively reduces ventilation requirements in hypercapnic patients: a pilot study

Abstract Background Lung-protective strategies are the cornerstone of mechanical ventilation in critically ill patients with both ARDS and other disorders. Extracorporeal CO2 removal (ECCO2R) may enhance lung protection by allowing even further reductions in tidal volumes and is effective in low-flow settings commonly used for renal replacement therapy. In this study, we describe for the first time the effects of a labeled and certified system combining ECCO2R and renal replacement therapy on pulmonary stress and strain in hypercapnic patients with renal failure. Methods Twenty patients were treated with the combined system which incorporates a membrane lung (0.32 m2) in a conventional renal replacement circuit. After changes in blood gases under ECCO2R were recorded, baseline hypercapnia was reestablished and the impact on ventilation parameters such as tidal volume and driving pressure was recorded. Results The system delivered ECCO2R at rate of 43.4 ± 14.1 ml/min, PaCO2 decreased from 68.3 ± 11.8 to 61.8 ± 11.5 mmHg (p < 0.05) and pH increased from 7.18 ± 0.09 to 7.22 ± 0.08 (p < 0.05). There was a significant reduction in ventilation requirements with a decrease in tidal volume from 6.2 ± 0.9 to 5.4 ± 1.1 ml/kg PBW (p < 0.05) corresponding to a decrease in plateau pressure from 30.6 ± 4.6 to 27.7 ± 4.1 cmH2O (p < 0.05) and a decrease in driving pressure from 18.3 ± 4.3 to 15.6 ± 3.9 cmH2O (p < 0.05), indicating reduced pulmonary stress and strain. No complications related to the procedure were observed. Conclusions The investigated low-flow ECCO2R and renal replacement system can ameliorate respiratory acidosis and decrease ventilation requirements in hypercapnic patients with concomitant renal failure. Trial registration NCT02590575, registered 10/23/2015

Glycoprotein N of Human Cytomegalovirus Protects the Virus from Neutralizing Antibodies

<div><p>Herpes viruses persist in the infected host and are transmitted between hosts in the presence of a fully functional humoral immune response, suggesting that they can evade neutralization by antiviral antibodies. Human cytomegalovirus (HCMV) encodes a number of polymorphic highly glycosylated virion glycoproteins (g), including the essential envelope glycoprotein, gN. We have tested the hypothesis that glycosylation of gN contributes to resistance of the virus to neutralizing antibodies. Recombinant viruses carrying deletions in serine/threonine rich sequences within the glycosylated surface domain of gN were constructed in the genetic background of HCMV strain AD169. The deletions had no influence on the formation of the gM/gN complex and <em>in vitro</em> replication of the respective viruses compared to the parent virus. The gN-truncated viruses were significantly more susceptible to neutralization by a gN-specific monoclonal antibody and in addition by a number of gB- and gH-specific monoclonal antibodies. Sera from individuals previously infected with HCMV also more efficiently neutralized gN-truncated viruses. Immunization of mice with viruses that expressed the truncated forms of gN resulted in significantly higher serum neutralizing antibody titers against the homologous strain that was accompanied by increased antibody titers against known neutralizing epitopes on gB and gH. Importantly, neutralization activity of sera from animals immunized with gN-truncated virus did not exhibit enhanced neutralizing activity against the parental wild type virus carrying the fully glycosylated wild type gN. Our results indicate that the extensive glycosylation of gN could represent a potentially important mechanism by which HCMV neutralization by a number of different antibody reactivities can be inhibited.</p> </div

Amino acid sequences of the parent gN protein and the different gN deletions.

<p>The amino acid sequence of the gN strain AD169 (residues 1–101) is shown in the top row. Deletions of amino acids are indicated by dots for the truncated molecules. The putative signal sequence (residues 1–21, <a href="http://www.cbs.dtu.dk/services/SignalP/" target="_blank">http://www.cbs.dtu.dk/services/SignalP/</a>) and part of the membrane anchor domain (starting at residue 93, <a href="http://www.cbs.dtu.dk/services/TMHMM/" target="_blank">http://www.cbs.dtu.dk/services/TMHMM/</a>) are indicated by bold letters.</p

Monoclonal antibodies to gB, gH and gN neutralize the gN-truncated viruses more efficiently than the parent virus.

<p>Virus and antibody were incubated for 1 h at 37°C and the mixture was added to HFF monolayers. Cells were washed 4 h later and percent infected cells was determined at 24 h post infection by indirect immunofluorescence using an antibody specific for IE-1. Target proteins and the corresponding mab are indicated. Every mab was tested at least two times with similar results. Data were analyzed by 2way ANOVA and Bonferroni posttests. * p<0.05, **p<0.01, ***p<0.001.</p

Murine sera raised against the gN-truncated viruses show increased neutralization capacity for the gN-truncated viruses.

<p>At an interval of 4 weeks, Balb/c mice were twice immunized i.p. with 5 µg each of gradient purified RVAD169, RVgN-41sig and RVgN-61sig, respectively. Four weeks after the second immunization, animals were boosted with 2 µg virions i.v. and the serum was collected 2 weeks later. Each pool consisted of sera from 3 animals. A) ELISA assay of the pooled sera using gradient purified virus as antigen (left panel) and purified recombinant gB (right panel). Mock: Serum pool from control mice immunized with PBS. 27–287: gB specific mab. B) Neutralization capacity of the serum pools against wild type and the gN-truncated viruses. The serum pools were tested twice with similar results.</p

Truncations in gN do not prevent gM/gN complex formation.

<p>Cos7 cells were transfected with the indicated plasmids, and protein expression was assayed by reactivity with mab 14-16A (anti-gM/gN), anti-myc (detection of gN) and anti-TGN46 (trans-Golgi apparatus). Reactivity was detected with the appropriate secondary antibodies. The appearance of yellow in the merged pictures indicates colocalization of proteins. In the merge panel cell nuclei are also stained blue.</p

Mechanistic aspects of neutralization.

<p>A) Parent virus and gN-truncated viruses adsorb comparably to fibroblasts. Virus (m.o.i. 0.5) was incubated with the indicated antibodies (5 µg/ml) for 1 h at 37°C and cooled to 4°C. The virus/antibody mixture was added to HFF and incubated for 1 h at 4°C. Lysates were prepared and processed for quantitative real time PCR analysis. The virus only sample was set to 100% and used to calculate the remaining samples. B) Post-adsorption neutralization is enhanced for gN-truncated viruses. HFF were adsorbed with virus at a m.o.i. of 0.2 at 4°C for 1 h. Antibody at the indicated concentrations was added and the culture was shifted to 37°C. Extent of infection was analyzed 24 h later by indirect immunofluorescence using an antibody for IE-1. C) gN-truncated viruses are neutralized with faster kinetic than the parent virus. Virus and antibody were mixed at 4°C and added to precooled HFF monolayer cells. The mixture was incubated for the indicated time at 37°C and the percent infected cells was determined at 24 h post infection by indirect immunofluorescence using an antibody specific for IE-1.</p