1,426 research outputs found
Impact of CT-apelin and NT-proBNP on identifying non-responders to cardiac resynchronization therapy
CONTEXT: Assessment of response to cardiac resynchronization therapy (CRT) is essential. OBJECTIVE: To assess the predictive value of CT-apelin together with NT-proBNP in patients undergoing CRT. METHODS: Serum CT-apelin and NT-proBNP were measured by ELISA before, and 6-month after CRT. Primary endpoint was non-response (<4% increase in LVEF) after 6-month. RESULTS: From 81 patients, 15 proved to be non-responders. Six-month CT-apelin was superior compared to NT-proBNP in identifying non-responders by multivariate ROC (CT-apelin:p = 0.01, NT-proBNP:p = 0.13) and by logistic regression (CT-apelin:p = 0.01, NT-proBNP:p = 0.41) analyzes. CONCLUSION: Six-month CT-apelin might be valuable novel biomarker in identifying non-responders to CRT that was superior to NT-proBNP
Using high angular resolution diffusion imaging data to discriminate cortical regions
Brodmann's 100-year-old summary map has been widely used for cortical localization in neuroscience. There is a pressing need to update this map using non-invasive, high-resolution and reproducible data, in a way that captures individual variability. We demonstrate here that standard HARDI data has sufficiently diverse directional variation among grey matter regions to inform parcellation into distinct functional regions, and that this variation is reproducible across scans. This characterization of the signal variation as non-random and reproducible is the critical condition for successful cortical parcellation using HARDI data. This paper is a first step towards an individual cortex-wide map of grey matter microstructure, The gray/white matter and pial boundaries were identified on the high-resolution structural MRI images. Two HARDI data sets were collected from each individual and aligned with the corresponding structural image. At each vertex point on the surface tessellation, the diffusion-weighted signal was extracted from each image in the HARDI data set at a point, half way between gray/white matter and pial boundaries. We then derived several features of the HARDI profile with respect to the local cortical normal direction, as well as several fully orientationally invariant features. These features were taken as a fingerprint of the underlying grey matter tissue, and used to distinguish separate cortical areas. A support-vector machine classifier, trained on three distinct areas in repeat 1 achieved 80-82% correct classification of the same three areas in the unseen data from repeat 2 in three volunteers. Though gray matter anisotropy has been mostly overlooked hitherto, this approach may eventually form the foundation of a new cortical parcellation method in living humans. Our approach allows for further studies on the consistency of HARDI based parcellation across subjects and comparison with independent microstructural measures such as ex-vivo histology
Simple synthesis of 32P-labelled inositol hexakisphosphates for study of phosphate transformations
In many soils inositol hexakisphosphate in its various forms is as abundant as inorganic phosphate. The organismal and geochemical processes that exchange phosphate between inositol hexakisphosphate and other pools of soil phosphate are poorly defined, as are the organisms and enzymes involved. We rationalized that simple enzymic synthesis of inositol hexakisphosphate labeled with 32P would greatly enable study of transformation of soil inositol phosphates when combined with robust HPLC separations of different inositol phosphates
The Opportunistic Pathogen Propionibacterium acnes: Insights into Typing, Human Disease, Clonal Diversification and CAMP Factor Evolution
We previously described a Multilocus Sequence Typing (MLST) scheme based on eight genes that facilitates population
genetic and evolutionary analysis of P. acnes. While MLST is a portable method for unambiguous typing of bacteria, it is
expensive and labour intensive. Against this background, we now describe a refined version of this scheme based on two
housekeeping (aroE; guaA) and two putative virulence (tly; camp2) genes (MLST4) that correctly predicted the phylogroup
(IA1, IA2, IB, IC, II, III), clonal complex (CC) and sequence type (ST) (novel or described) status for 91% isolates (n = 372) via
cross-referencing of the four gene allelic profiles to the full eight gene versions available in the MLST database (http://
pubmlst.org/pacnes/). Even in the small number of cases where specific STs were not completely resolved, the MLST4
method still correctly determined phylogroup and CC membership. Examination of nucleotide changes within all the MLST
loci provides evidence that point mutations generate new alleles approximately 1.5 times as frequently as recombination;
although the latter still plays an important role in the bacteriumâs evolution. The secreted/cell-associated âvirulenceâ factors
tly and camp2 show no clear evidence of episodic or pervasive positive selection and have diversified at a rate similar to
housekeeping loci. The co-evolution of these genes with the core genome might also indicate a role in commensal/normal
existence constraining their diversity and preventing their loss from the P. acnes population. The possibility that members of
the expanded CAMP factor protein family, including camp2, may have been lost from other propionibacteria, but not P.
acnes, would further argue for a possible role in niche/host adaption leading to their retention within the genome. These
evolutionary insights may prove important for discussions surrounding camp2 as an immunotherapy target for acne, and
the effect such treatments may have on commensal lineages
FRA2 is a STAT5 target gene regulated by IL-2 in human CD4 T cells
Signal transducers and activators of transcription 5(STAT5) are cytokine induced signaling proteins, which regulate key immunological processes, such as tolerance induction, maintenance of homeostasis, and CD4 T-effector cell differentiation. In this study, transcriptional targets of STAT5 in CD4 T cells were studied by Chromatin Immunoprecipitation (ChIP). Genomic mapping of the sites cloned and identified in this study revealed the striking observation that the majority of STAT5-binding sites mapped to intergenic (>50 kb upstream) or intronic, rather than promoter proximal regions. Of the 105 STAT5 responsive binding sites identified, 94% contained the canonical (IFN-Îł activation site) GAS motifs. A number of putative target genes identified here are associated with tumor biology. Here, we identified Fos-related antigen 2 (FRA2) as a transcriptional target of IL-2 regulated STAT5. FRA2 is a basic -leucine zipper (bZIP) motif 'Fos' family transcription factor that is part of the AP-1 transcription factor complex and is also known to play a critical role in the progression of human tumours and more recently as a determinant of T cell plasticity. The binding site mapped to an internal intron within the FRA2 gene. The epigenetic architecture of FRA2, characterizes a transcriptionally active promoter as indicated by enrichment for histone methylation marks H3K4me1, H3K4me2, H3K4me3, and transcription/elongation associated marks H2BK5me1 and H4K20me1. FRA2 is regulated by IL-2 in activated CD4 T cells. Consistently, STAT5 bound to GAS sequence in the internal intron of FRA2 and reporter gene assays confirmed IL-2 induced STAT5 binding and transcriptional activation. Furthermore, addition of JAK3 inhibitor (R333) or Daclizumab inhibited the induction in TCR stimulated cells. Taken together, our data suggest that FRA2 is a novel STAT5 target gene, regulated by IL-2 in activated CD4 T cells
UPF1, a Conserved Nonsense-Mediated mRNA Decay Factor, Regulates Cyst Wall Protein Transcripts in Giardia lamblia
The Giardia lamblia cyst wall is required for survival outside the host and infection. Three cyst wall protein (cwp) genes identified to date are highly up-regulated during encystation. However, little is known of the molecular mechanisms governing their gene regulation. Messenger RNAs containing premature stop codons are rapidly degraded by a nonsense-mediated mRNA decay (NMD) system to avoid production of non-functional proteins. In addition to RNA surveillance, NMD also regulates thousands of naturally occurring transcripts through a variety of mechanisms. It is interesting to know the NMD pathway in the primitive eukaryotes. Previously, we have found that the giardial homologue of a conserved NMD factor, UPF1, may be functionally conserved and involved in NMD and in preventing nonsense suppression. In this study, we tested the hypothesis that NMD factors can regulate some naturally occurring transcripts in G. lamblia. We found that overexpression of UPF1 resulted in a significant decrease of the levels of CWP1 and cyst formation and of the endogenous cwp1-3, and myb2 mRNA levels and stability. This indicates that NMD could contribute to the regulation of the cwp1-3 and myb2 transcripts, which are key to G. lamblia differentiation into cyst. Interestingly, we also found that UPF1 may be involved in regulation of eight other endogenous genes, including up-regulation of the translation elongation factor gene, whose product increases translation which is required for NMD. Our results indicate that NMD factor could contribute to the regulation of not only nonsense containing mRNAs, but also mRNAs of the key encystation-induced genes and other endogenous genes in the early-diverging eukaryote, G. lamblia
An Ancient Duplication of Exon 5 in the Snap25 Gene Is Required for Complex Neuronal Development/Function
Alternative splicing is an evolutionary innovation to create functionally diverse proteins from a limited number of genes. SNAP-25 plays a central role in neuroexocytosis by bridging synaptic vesicles to the plasma membrane during regulated exocytosis. The SNAP-25 polypeptide is encoded by a single copy gene, but in higher vertebrates a duplication of exon 5 has resulted in two mutually exclusive splice variants, SNAP-25a and SNAP-25b. To address a potential physiological difference between the two SNAP-25 proteins, we generated gene targeted SNAP-25b deficient mouse mutants by replacing the SNAP-25b specific exon with a second SNAP-25a equivalent. Elimination of SNAP-25b expression resulted in developmental defects, spontaneous seizures, and impaired short-term synaptic plasticity. In adult mutants, morphological changes in hippocampus and drastically altered neuropeptide expression were accompanied by severe impairment of spatial learning. We conclude that the ancient exon duplication in the Snap25 gene provides additional SNAP-25-function required for complex neuronal processes in higher eukaryotes
Analysis of the effects of depression associated polymorphisms on the activity of the BICC1 promoter in amygdala neurones
ACKNOWLEDGMENTS This work was funded by The BBSRC (BB/D004659/1) the Wellcome Trust (080980/Z/06/Z) and the Medical Research Council (G0701003).Peer reviewedPublisher PD
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at â s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fbâ1 of â s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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