1,546 research outputs found

    The effect of regional citrate anti-coagulation on the coagulation system in critically ill patients receiving continuous renal replacement therapy for acute kidney injury - An observational cohort study

    Get PDF
    BACKGROUND: Regional anticoagulation with citrate is the recommended first line treatment for patients receiving continuous renal replacement therapy (CRRT). There is wide variability in filter patency which may be due to differences in patient characteristics and local practice. It is also possible that citrate has effects on primary and secondary haemostasis, fibrinolysis and platelet function that are still unknown. The primary aim of the study is to describe the effect of citrate on coagulation and fibrinolysis pathways in both the patient and the haemodialysis circuit. METHODS: The study will recruit 12 adult patients admitted to the intensive care unit, requiring CRRT with regional citrate anticoagulation for acute kidney injury. Patients with pre-existing thrombotic or bleeding tendencies will be excluded. Thrombin generation, clot lysis and platelet function will be measured at baseline and at 12, 24, 36, 48 and 72 h after commencing CRRT (from the patient and from the circuit). We will describe the evolution of parameters over time as well as the differences in parameters between the patient and the circuit. DISCUSSION: The study will provide new data on the effects of citrate during continuous renal replacement therapy which is not currently available. We will minimise confounding factors through the use of tight exclusion criteria and accept that this will slow down recruitment. Depending on the results, we hope to incorporate the findings into existing clinical guidelines and clinical practice with the aim to prevent premature filter clotting and interruptions in treatment. TRIAL REGISTRATION: The study was registered with clinicaltrials.gov on 10th June 2015 (NCT02486614)

    Topological Analysis of Metabolic Networks Integrating Co-Segregating Transcriptomes and Metabolomes in Type 2 Diabetic Rat Congenic Series

    Get PDF
    Background: The genetic regulation of metabolic phenotypes (i.e., metabotypes) in type 2 diabetes mellitus is caused by complex organ-specific cellular mechanisms contributing to impaired insulin secretion and insulin resistance. Methods: We used systematic metabotyping by 1H NMR spectroscopy and genome-wide gene expression in white adipose tissue to map molecular phenotypes to genomic blocks associated with obesity and insulin secretion in a series of rat congenic strains derived from spontaneously diabetic Goto-Kakizaki (GK) and normoglycemic Brown-Norway (BN) rats. We implemented a network biology strategy approach to visualise shortest paths between metabolites and genes significantly associated with each genomic block. Results: Despite strong genomic similarities (95-99%) among congenics, each strain exhibited specific patterns of gene expression and metabotypes, reflecting metabolic consequences of series of linked genetic polymorphisms in the congenic intervals. We subsequently used the congenic panel to map quantitative trait loci underlying specific metabotypes (mQTL) and genome-wide expression traits (eQTL). Variation in key metabolites like glucose, succinate, lactate or 3-hydroxybutyrate, and second messenger precursors like inositol was associated with several independent genomic intervals, indicating functional redundancy in these regions. To navigate through the complexity of these association networks we mapped candidate genes and metabolites onto metabolic pathways and implemented a shortest path strategy to highlight potential mechanistic links between metabolites and transcripts at colocalized mQTLs and eQTLs. Minimizing shortest path length drove prioritization of biological validations by gene silencing. Conclusions: These results underline the importance of network-based integration of multilevel systems genetics datasets to improve understanding of the genetic architecture of metabotype and transcriptomic regulations and to characterize novel functional roles for genes determining tissue-specific metabolism

    Fear Conditioning to Subliminal Fear Relevant and Non Fear Relevant Stimuli

    Get PDF
    A growing body of evidence suggests that conscious visual awareness is not a prerequisite for human fear learning. For instance, humans can learn to be fearful of subliminal fear relevant images – images depicting stimuli thought to have been fear relevant in our evolutionary context, such as snakes, spiders, and angry human faces. Such stimuli could have a privileged status in relation to manipulations used to suppress usually salient images from awareness, possibly due to the existence of a designated sub-cortical β€˜fear module’. Here we assess this proposition, and find it wanting. We use binocular masking to suppress awareness of images of snakes and wallabies (particularly cute, non-threatening marsupials). We find that subliminal presentations of both classes of image can induce differential fear conditioning. These data show that learning, as indexed by fear conditioning, is neither contingent on conscious visual awareness nor on subliminal conditional stimuli being fear relevant

    Building block libraries and structural considerations in the self-assembly of polyoxometalate and polyoxothiometalate systems

    Get PDF
    Inorganic metal-oxide clusters form a class of compounds that are unique in their topological and electronic versatility and are becoming increasingly more important in a variety of applications. Namely, Polyoxometalates (POMs) have shown an unmatched range of physical properties and the ability to form structures that can bridge several length scales. The formation of these molecular clusters is often ambiguous and is governed by self-assembly processes that limit our ability to rationally design such molecules. However, recent years have shown that by considering new building block principles the design and discovery of novel complex clusters is aiding our understanding of this process. Now with current progress in thiometalate chemistry, specifically polyoxothiometalates (POTM), the field of inorganic molecular clusters has further diversified allowing for the targeted development of molecules with specific functionality. This chapter discusses the main differences between POM and POTM systems and how this affects synthetic methodologies and reactivities. We will illustrate how careful structural considerations can lead to the generation of novel building blocks and further deepen our understanding of complex systems

    Molecular epidemiology of methicillin-resistant Staphylococcus aureus isolated from Australian veterinarians

    Get PDF
    This work investigated the molecular epidemiology and antimicrobial resistance of methicillinresistant Staphylococcus aureus (MRSA) isolated from veterinarians in Australia in 2009. The collection (n = 44) was subjected to extensive molecular typing (MLST, spa, SCCmec, dru, PFGE, virulence and antimicrobial resistance genotyping) and antimicrobial resistance phenotyping by disk diffusion. MRSA was isolated from Australian veterinarians representing various occupational emphases. The isolate collection was dominated by MRSA strains belonging to clonal complex (CC) 8 and multilocus sequence type (ST) 22. CC8 MRSA (ST8-IV [2B], spa t064; and ST612-IV [2B] , spa variable,) were strongly associated with equine practice veterinarians (OR = 17.5, 95% CI = 3.3-92.5, P < 0.001) and were often resistant to gentamicin and rifampicin. ST22-IV [2B], spa variable, were strongly associated with companion animal practice veterinarians (OR = 52.5, 95% CI = 5.2-532.7, P < 0.001) and were resistant to ciprofloxacin. A single pig practice veterinarian carried ST398-V [5C2], spa t1451. Equine practice and companion animal practice veterinarians frequently carried multiresistant-CC8 and ST22 MRSA, respectively, whereas only a single swine specialist carried MRSA ST398. The presence of these strains in veterinarians may be associated with specific antimicrobial administration practices in each animal species

    Carotid artery injury from an airgun pellet: a case report and review of the literature

    Get PDF
    Historically airguns were powerful weapons. Modern models, though less lethal, are still capable of inflicting serious or life threatening injuries. Current United Kingdom legislation fails to take into the account the capacity for airguns to maim and kill. We believe that airguns should be governed by the same law that applies to firearms. We present a case of a potentially fatal airgun injury to the neck. The airgun pellet caused a defect in the anterior wall of the external carotid artery, which required rapid access and surgical repair. We discuss the mechanism of airgun injury and review the literature in terms of investigation and management

    The Impact of Simulated Sulfate Deposition on Peatland Testate Amoebae

    Get PDF
    Peatlands subjected to sulfate deposition have been shown to produce less methane, believed to be due to competitive exclusion of methanogenic archaea by sulfate-reducing bacteria. Here, we address whether sulfate deposition produces impacts on a higher microbial group, the testate amoebae. Sodium sulfate was applied to experimental plots on a Scottish peatland and samples extracted after a period of more than 10 years. Impacts on testate amoebae were tested using redundancy analysis and Mann-Whitney tests. Results showed statistically significant impacts on amoebae communities particularly noted by decreased abundance of Trinema lineare, Corythion dubium, and Euglypha rotunda. As the species most reduced in abundance are all small bacterivores we suggest that our results support the hypothesis of a shift in dominant prokaryotes, although other explanations are possible. Our results demonstrate the sensitivity of peatland microbial communities to sulfate deposition and suggest sulfate may be a potentially important secondary control on testate amoebae communities

    Distinct Mechanisms for Induction and Tolerance Regulate the Immediate Early Genes Encoding Interleukin 1Ξ² and Tumor Necrosis Factor Ξ±

    Get PDF
    Interleukin-1Ξ² and Tumor Necrosis Factor Ξ± play related, but distinct, roles in immunity and disease. Our study revealed major mechanistic distinctions in the Toll-like receptor (TLR) signaling-dependent induction for the rapidly expressed genes (IL1B and TNF) coding for these two cytokines. Prior to induction, TNF exhibited pre-bound TATA Binding Protein (TBP) and paused RNA Polymerase II (Pol II), hallmarks of poised immediate-early (IE) genes. In contrast, unstimulated IL1B displayed very low levels of both TBP and paused Pol II, requiring the lineage-specific Spi-1/PU.1 (Spi1) transcription factor as an anchor for induction-dependent interaction with two TLR-activated transcription factors, C/EBPΞ² and NF-ΞΊB. Activation and DNA binding of these two pre-expressed factors resulted in de novo recruitment of TBP and Pol II to IL1B in concert with a permissive state for elongation mediated by the recruitment of elongation factor P-TEFb. This Spi1-dependent mechanism for IL1B transcription, which is unique for a rapidly-induced/poised IE gene, was more dependent upon P-TEFb than was the case for the TNF gene. Furthermore, the dependence on phosphoinositide 3-kinase for P-TEFb recruitment to IL1B paralleled a greater sensitivity to the metabolic state of the cell and a lower sensitivity to the phenomenon of endotoxin tolerance than was evident for TNF. Such differences in induction mechanisms argue against the prevailing paradigm that all IE genes possess paused Pol II and may further delineate the specific roles played by each of these rapidly expressed immune modulators. Β© 2013 Adamik et al

    Effects of deletion of the Streptococcus pneumoniae lipoprotein diacylglyceryl transferase gene lgt on ABC transporter function and on growth in vivo

    Get PDF
    Lipoproteins are an important class of surface associated proteins that have diverse roles and frequently are involved in the virulence of bacterial pathogens. As prolipoproteins are attached to the cell membrane by a single enzyme, prolipoprotein diacylglyceryl transferase (Lgt), deletion of the corresponding gene potentially allows the characterisation of the overall importance of lipoproteins for specific bacterial functions. We have used a Ξ”lgt mutant strain of Streptococcus pneumoniae to investigate the effects of loss of lipoprotein attachment on cation acquisition, growth in media containing specific carbon sources, and virulence in different infection models. Immunoblots of triton X-114 extracts, flow cytometry and immuno-fluorescence microscopy confirmed the Ξ”lgt mutant had markedly reduced lipoprotein expression on the cell surface. The Ξ”lgt mutant had reduced growth in cation depleted medium, increased sensitivity to oxidative stress, reduced zinc uptake, and reduced intracellular levels of several cations. Doubling time of the Ξ”lgt mutant was also increased slightly when grown in medium with glucose, raffinose and maltotriose as sole carbon sources. These multiple defects in cation and sugar ABC transporter function for the Ξ”lgt mutant were associated with only slightly delayed growth in complete medium. However the Ξ”lgt mutant had significantly reduced growth in blood or bronchoalveolar lavage fluid and a marked impairment in virulence in mouse models of nasopharyngeal colonisation, sepsis and pneumonia. These data suggest that for S. pneumoniae loss of surface localisation of lipoproteins has widespread effects on ABC transporter functions that collectively prevent the Ξ”lgt mutant from establishing invasive infection
    • …
    corecore