71 research outputs found

    Candida auris-Macrophage Cellular Interactions and Transcriptional Response

    Get PDF
    The pathogenic yeast Candida auris represents a global threat of the utmost clinical relevance. This emerging fungal species is remarkable in its resistance to commonly used antifungal agents and its persistence in the nosocomial settings. The innate immune system is one the first lines of defense preventing the dissemination of pathogens in the host. C. auris is susceptible to circulating phagocytes, and understanding the molecular details of these interactions may suggest routes to improved therapies. In this work, we examined the interactions of this yeast with macrophages. We found that macrophages avidly phagocytose C. auris; however, intracellular replication is not inhibited, indicating that C. auris resists the killing mechanisms imposed by the phagocyte. Unlike Candida albicans, phagocytosis of C. auris does not induce macrophage lysis. The transcriptional response of C. auris to macrophage phagocytosis is very similar to other members of the CUG clade (C. albicans, C. tropicalis, C. parapsilosis, C. lusitaniae), i.e., downregulation of transcription/translation and upregulation of alternative carbon metabolism pathways, transporters, and induction of oxidative stress response and proteolysis. Gene family expansions are common in this yeast, and we found that many of these genes are induced in response to macrophage co-incubation. Among these, amino acid and oligopeptide transporters, as well as lipases and proteases, are upregulated. Thus, C. auris shares key transcriptional signatures shared with other fungal pathogens and capitalizes on the expansion of gene families coding for potential virulence attributes that allow its survival, persistence, and evasion of the innate immune system

    The stroke oxygen pilot study: a randomized control trial of the effects of routine oxygen supplementation early after acute stroke--effect on key outcomes at six months

    Get PDF
    Introduction: Post-stroke hypoxia is common, and may adversely affect outcome. We have recently shown that oxygen supplementation may improve early neurological recovery. Here, we report the six-month outcomes of this pilot study. Methods: Patients with a clinical diagnosis of acute stroke were randomized within 24 h of admission to oxygen supplementation at 2 or 3 L/min for 72 h or to control treatment (room air). Outcomes (see below) were assessed by postal questionnaire at 6 months. Analysis was by intention-to-treat, and statistical significance was set at p#0.05. Results: Out of 301 patients randomized two refused/withdrew consent and 289 (148 in the oxygen and 141 in the control group) were included in the analysis: males 44%, 51%; mean (SD) age 73 (12), 71 (12); median (IQR) National Institutes of Health Stroke Scale score 6 (3, 10), 5 (3, 10) for the two groups respectively. At six months 22 (15%) patients in the oxygen group and 20 (14%) in the control group had died; mean survival in both groups was 162 days (p= 0.99). Median (IQR) scores for the primary outcome, the modified Rankin Scale, were 3 (1, 5) and 3 (1, 4) for the oxygen and control groups respectively. The covariate-adjusted odds ratio was 1.04 (95% CI 0.67, 1.60), indicating that the odds of a lower (i.e. better) score were non-significantly higher in the oxygen group (p= 0.86). The mean differences in the ability to perform basic (Barthel Index) and extended activities of daily living (NEADL), and quality of life (EuroQol) were also non-significant. Conclusions: None of the key outcomes differed at 6 months between the groups. Although not statistically significant and generally of small magnitude, the effects were predominantly in favour of the oxygen group; a larger trial, powered to show differences in longer-term functional outcomes, is now on-going. Trial Registration: Controlled-Trials.com ISRCTN12362720; Eudract.ema.europa.eu 2004-001866-4

    Veterinary trypanocidal benzoxaboroles are peptidase-activated prodrugs

    Get PDF
    Livestock diseases caused by Trypanosoma congolense, T. vivax and T. brucei, collectively known as nagana, are responsible for billions of dollars in lost food production annually. There is an urgent need for novel therapeutics. Encouragingly, promising antitrypanosomal benzoxaboroles are under veterinary development. Here, we show that the most efficacious subclass of these compounds are prodrugs activated by trypanosome serine carboxypeptidases (CBPs). Drug-resistance to a development candidate, AN11736, emerged readily in T. brucei, due to partial deletion within the locus containing three tandem copies of the CBP genes. T. congolense parasites, which possess a larger array of related CBPs, also developed resistance to AN11736 through deletion within the locus. A genome-scale screen in T. brucei confirmed CBP loss-of-function as the primary mechanism of resistance and CRISPR-Cas9 editing proved that partial deletion within the locus was sufficient to confer resistance. CBP re-expression in either T. brucei or T. congolense AN11736-resistant lines restored drug-susceptibility. CBPs act by cleaving the benzoxaborole AN11736 to a carboxylic acid derivative, revealing a prodrug activation mechanism. Loss of CBP activity results in massive reduction in net uptake of AN11736, indicating that entry is facilitated by the concentration gradient created by prodrug metabolism.</p

    Smoke gets in your eyes: re-reading gender in the "nostalgia film"

    Get PDF
    Upon its release, American Graffiti (George Lucas, 1973) was much admired by critics and audiences alike. Yet, in subsequent years, the film became known for its supposed “flattening of history,” and celebration of patriarchal values. This article demonstrates that such a judgement owes much to Fredric Jameson’s historically contingent work on postmodernism, which argues that American Graffiti constitutes the paradigmatic nostalgia film. In contrast, using close textual analysis, I demonstrate that American Graffiti provides a more complex construction of the past, and of gender, than has hitherto been acknowledged. Far from blindly idealising the early 1960s, the film interrogates the processes through which the period and its gender relations come to be idealised. This article has consequences not only for our understanding of Lucas’ seminal film, but also for the American New Wave, and the “nostalgia” text

    Investigation of type 1 diabetes and coeliac disease susceptibility loci for association with juvenile idiopathic arthritis

    Get PDF
    BACKGROUND: There is strong evidence suggesting that juvenile idiopathic arthritis (JIA) shares many susceptibility loci with other autoimmune diseases. OBJECTIVE: To investigate variants robustly associated with type 1 diabetes (T1D) or coeliac disease (CD) for association with JIA. METHODS: Sixteen single-nucleotide polymorphisms (SNPs) already identified as susceptibility loci for T1D/CD were selected for genotyping in patients with JIA (n=1054) and healthy controls (n=3129). Genotype and allele frequencies were compared using the Cochrane-Armitage trend test implemented in PLINK. RESULTS: One SNP in the LPP gene, rs1464510, showed significant association with JIA (p(trend)=0.002, OR=1.18, 95% CI 1.06 to 1.30). A second SNP, rs653178 in ATXN2, also showed nominal evidence for association with JIA (p(trend)=0.02, OR=1.13, 95% CI 1.02 to 1.25). The SNP, rs17810546, in IL12A showed subtype-specific association with enthesitis-related arthritis (ERA) subtype (p(trend)=0.005, OR=1.88, 95% CI 1.2 to 2.94). CONCLUSIONS: Evidence for a novel JIA susceptibility locus, LPP, is presented. Association at the SH2B3/ATXN2 locus, previously reported to be associated with JIA in a US series, also supports this region as contributing to JIA susceptibility. In addition, a subtype-specific association of IL12A with ERA is identified. All findings will require validation in independent JIA cohorts

    Deletion of transketolase triggers a stringent metabolic response in promastigotes and loss of virulence in amastigotes of Leishmania mexicana

    Get PDF
    Transketolase (TKT) is part of the non-oxidative branch of the pentose phosphate pathway (PPP). Here we describe the impact of removing this enzyme from the pathogenic protozoan Leishmania mexicana. Whereas the deletion had no obvious effect on cultured promastigote forms of the parasite, the Δtkt cells were not infective to mice. Δtkt promastigotes were more susceptible to oxidative stress and various leishmanicidal drugs than wild-type, and metabolomics analysis revealed profound changes to metabolism in these cells. In addition to changes consistent with those directly related to the role of TKT in the PPP, central carbon metabolism was substantially decreased, the cells consumed significantly less glucose, flux through glycolysis diminished, and production of the main end products of metabolism was decreased. Only minor changes in RNA abundance from genes encoding enzymes in central carbon metabolism, however, were detected although fructose-1,6-bisphosphate aldolase activity was decreased two-fold in the knock-out cell line. We also showed that the dual localisation of TKT between cytosol and glycosomes is determined by the C-terminus of the enzyme and by engineering different variants of the enzyme we could alter its sub-cellular localisation. However, no effect on the overall flux of glucose was noted irrespective of whether the enzyme was found uniquely in either compartment, or in both

    Speaking in a second language but thinking in the first language: Language-specific effects on memory for causation events in English and Spanish

    Get PDF
    Aims and objectives/purpose/research question: This paper’s objective is to offer new insights into the effects of language on memory for causation events in a second language (L2) context. The research was driven by the question of whether proficient L2 users acquired L2 thinking-for-speaking-and-remembering strategies along with the relevant expressions for different types of causation (intentional versus non-intentional). Design/methodology/approach: The cognitive domain of causation is an ideal platform for this investigation, since the lexicalisation of causation differs clearly in the two languages under consideration, English and Spanish. Spanish speakers always distinguish between intentional and non-intentional events through the use of different constructions. The English pattern of lexicalisation in this domain often leaves intentionality unspecified. Our methodology involves an experimental elicitation of event verbalisations and recall memory responses to video stimuli by English and Spanish monolinguals and bilinguals. Data and analysis: The analysis has shown that the Spanish monolinguals and first language (L1) Spanish/L2 English speakers always distinguished between intentional and non-intentional events, while the English monolinguals and L1 English/L2 Spanish speakers generally used expressions that were underspecified with regard to intentionality. Findings/conclusions: All populations used their habitual language patterns as an aid to memory. Spanish monolingual had better recall than their English peers. L2 speakers were mainly relying on the L1 in spite of speaking only the L2 during the experiment. Originality: Possible effects of these typological differences between an L1 and an L2 on speaker recall memory have not been investigated before. Significance/implications: The research presented in this paper informs the theoretical assumptions related to the thinking-for-speaking hypothesis by showing empirically that late bilinguals adhere to their L1 patterns as an aid to memory while speaking in their L2. This novel finding contributes to an improved understanding of language processing and language use among late bilinguals
    corecore