135 research outputs found

    High viral load of Merkel cell polyomavirus DNA sequences in Langerhans cell sarcoma tissues.

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    International audienceBACKGROUND: Langerhans cell (LC) sarcoma (LCS) is a high-grade neoplasm with overtly malignant cytologic features and an LC phenotype. We very recently suggested that LC behaves as a reservoir for common dermotropic Merkel cell polyomavirus (MCPyV) and determined the relationship between LC histiocytosis (LCH), which has an underlining oncogenic capacity, and MCPyV as a trigger for a reactive process rather than a neoplastic process. We propose LC to be a reservoir for MCPyV and hypothesize that some LCS subtypes may be related to the MCPyV agent. FINDINGS: We examined seven LCS tissues using multiplex quantitative PCR (Q-PCR) and immunohistochemistry with anti MCPyV large-T (LT) antigen antibody. High viral loads of MCPyV DNA sequences (viral load = relative levels of MCPyV) were detected (0.328-0.772 copies/cell (Merkel cell carcinoma (MCC) = 1.0)) using Q-PCR in 43% (3/7) tissues, but LT antigen expression was not observed (0/7). CONCLUSIONS: Frequent MCPyV-DNA amplification suggests that LCS in some patients may be related to MCPyV infection. Moreover, the higher viral load of LCS (median, 0.453 copies/cell) than low load of LCH (0.003, median of 12 cases) (P < 0.01) may suggest a virally induced tumorigenic process in some LCS. Although the absence of LT antigen expression may indicate a different role for MCPyV in this pathology, some subtypes of LCS may develop in the background of MCPyV-infected LC. To the best of our knowledge, this is the first report on the relationship between MCPyV and LCS. The recent discovery of MCPyV opened new therapeutic avenues for MCC. These data open novel possibilities for therapeutic interventions against LCS

    Actinomycete integrative and conjugative elements

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    This paper reviews current knowledge on actinomycete integrative and conjugative elements (AICEs). The best characterised AICEs, pSAM2 of Streptomyces ambofaciens (10.9 kb), SLP1 (17.3 kb) of Streptomyces coelicolor and pMEA300 of Amycolatopsis methanolica (13.3 kb), are present as integrative elements in specific tRNA genes, and are capable of conjugative transfer. These AICEs have a highly conserved structural organisation, with functional modules for excision/integration, replication, conjugative transfer, and regulation. Recently, it has been shown that pMEA300 and the related elements pMEA100 of Amycolatopsis mediterranei and pSE211 of Saccharopolyspora erythraea form a novel group of AICEs, the pMEA-elements, based on the unique characteristics of their replication initiator protein RepAM. Evaluation of a large collection of Amycolatopsis isolates has allowed identification of multiple pMEA-like elements. Our data show that, as AICEs, they mainly coevolved with their natural host in an integrated form, rather than being dispersed via horizontal gene transfer. The pMEA-like elements could be separated into two distinct populations from different geographical origins. One group was most closely related to pMEA300 and was found in isolates from Australia and Asia and pMEA100-related sequences were present in European isolates. Genome sequence data have enormously contributed to the recent insight that AICEs are present in many actinomycete genera. The sequence data also provide more insight into their evolutionary relationships, revealing their modular composition and their likely combined descent from bacterial plasmids and bacteriophages. Evidence is accumulating that AICEs act as modulators of host genome diversity and are also involved in the acquisition of secondary metabolite clusters and foreign DNA via horizontal gene transfer. Although still speculative, these AICEs may play a role in the spread of antibiotic resistance factors into pathogenic bacteria. The novel insights on AICE characteristics presented in this review may be used for the effective construction of new vectors that allows us to engineer and optimise strains for the production of commercially and medically interesting secondary metabolites, and bioactive proteins

    Ligand-Dependent Conformations and Dynamics of the Serotonin 5-HT2A Receptor Determine Its Activation and Membrane-Driven Oligomerization Properties

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    From computational simulations of a serotonin 2A receptor (5-HT2AR) model complexed with pharmacologically and structurally diverse ligands we identify different conformational states and dynamics adopted by the receptor bound to the full agonist 5-HT, the partial agonist LSD, and the inverse agonist Ketanserin. The results from the unbiased all-atom molecular dynamics (MD) simulations show that the three ligands affect differently the known GPCR activation elements including the toggle switch at W6.48, the changes in the ionic lock between E6.30 and R3.50 of the DRY motif in TM3, and the dynamics of the NPxxY motif in TM7. The computational results uncover a sequence of steps connecting these experimentally-identified elements of GPCR activation. The differences among the properties of the receptor molecule interacting with the ligands correlate with their distinct pharmacological properties. Combining these results with quantitative analysis of membrane deformation obtained with our new method (Mondal et al, Biophysical Journal 2011), we show that distinct conformational rearrangements produced by the three ligands also elicit different responses in the surrounding membrane. The differential reorganization of the receptor environment is reflected in (i)-the involvement of cholesterol in the activation of the 5-HT2AR, and (ii)-different extents and patterns of membrane deformations. These findings are discussed in the context of their likely functional consequences and a predicted mechanism of ligand-specific GPCR oligomerization

    Value of hospital antimicrobial stewardship programs [ASPs]:a systematic review

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    Abstract Background Hospital antimicrobial stewardship programs (ASPs) aim to promote judicious use of antimicrobials to combat antimicrobial resistance. For ASPs to be developed, adopted, and implemented, an economic value assessment is essential. Few studies demonstrate the cost-effectiveness of ASPs. This systematic review aimed to evaluate the economic and clinical impact of ASPs. Methods An update to the Dik et al. systematic review (2000–2014) was conducted on EMBASE and Medline using PRISMA guidelines. The updated search was limited to primary research studies in English (30 September 2014–31 December 2017) that evaluated patient and/or economic outcomes after implementation of hospital ASPs including length of stay (LOS), antimicrobial use, and total (including operational and implementation) costs. Results One hundred forty-six studies meeting inclusion criteria were included. The majority of these studies were conducted within the last 5 years in North America (49%), Europe (25%), and Asia (14%), with few studies conducted in Africa (3%), South America (3%), and Australia (3%). Most studies were conducted in hospitals with 500–1000 beds and evaluated LOS and change in antibiotic expenditure, the majority of which showed a decrease in LOS (85%) and antibiotic expenditure (92%). The mean cost-savings varied by hospital size and region after implementation of ASPs. Average cost savings in US studies were 732perpatient(range:732 per patient (range: 2.50 to $2640), with similar trends exhibited in European studies. The key driver of cost savings was from reduction in LOS. Savings were higher among hospitals with comprehensive ASPs which included therapy review and antibiotic restrictions. Conclusions Our data indicates that hospital ASPs have significant value with beneficial clinical and economic impacts. More robust published data is required in terms of implementation, LOS, and overall costs so that decision-makers can make a stronger case for investing in ASPs, considering competing priorities. Such data on ASPs in lower- and middle-income countries is limited and requires urgent attention

    Not Quite Right: Representations of Eastern Europeans in ECJ Discourse

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    Although the increasing responsiveness of the Court of Justice of the European Union (the ‘ECJ’) jurisprudence to western Member States’ concerns regarding Central and Eastern European (‘CEE’) nationals’ mobility has garnered academic attention, ECJ discourse has not been scrutinised for how it approaches the CEE region or CEE movers. Applying postcolonial theory, this article seeks to fill this gap and to explore whether there are any indications that ECJ discourse is in line with the historical western-centric inferiorisation of the CEE region. A critical discourse analysis of a set of ECJ judgments and corresponding Advocate General opinions pertaining to CEE nationals illustrates not only how the ECJ adopts numerous discursive strategies to maintain its authority, but also how it tends to prioritise values of the western Member States, while overlooking interests of CEE movers. Its one-sided approach is further reinforced by referring to irrelevant facts and negative assumptions to create an image of CEE nationals as socially and economically inferior to westerners, as not belonging to the proper EU polity and as not quite deserving of EU law’s protections. By silencing CEE nationals’ voices, while disregarding the background of east/west socio-economic and political power differentials and precariousness experienced by many CEE workers in the west, such racialising discourse normalises ethnicity- and class-based stereotypes. These findings also help to contextualise both EU and western policies targeting CEE movers and evidence of their unequal outcomes in the west, and are in line with today’s nuanced expressions of racisms. By illustrating the ECJ’s role in addressing values pertinent to mobile CEE individuals, this study facilitates a fuller appreciation of the ECJ’s power in shaping and reflecting western-centric EU identity and policies. Engaging with such issues will not only allow us to better appreciate—and question—the ECJ’s legitimacy, but might also facilitate a better understanding of power dynamics within the EU. This study also makes significant theoretical and methodological contributions. It expands (and complicates) the application of postcolonial theory to contemporary intra-EU processes, while illustrating the usefulness of applying critical discourse analysis to exploring differentiation, exclusion, subordination and power within legal language

    Trace elements in glucometabolic disorders: an update

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    Many trace elements, among which metals, are indispensable for proper functioning of a myriad of biochemical reactions, more particularly as enzyme cofactors. This is particularly true for the vast set of processes involved in regulation of glucose homeostasis, being it in glucose metabolism itself or in hormonal control, especially insulin. The role and importance of trace elements such as chromium, zinc, selenium, lithium and vanadium are much less evident and subjected to chronic debate. This review updates our actual knowledge concerning these five trace elements. A careful survey of the literature shows that while theoretical postulates from some key roles of these elements had led to real hopes for therapy of insulin resistance and diabetes, the limited experience based on available data indicates that beneficial effects and use of most of them are subjected to caution, given the narrow window between safe and unsafe doses. Clear therapeutic benefit in these pathologies is presently doubtful but some data indicate that these metals may have a clinical interest in patients presenting deficiencies in individual metal levels. The same holds true for an association of some trace elements such as chromium or zinc with oral antidiabetics. However, this area is essentially unexplored in adequate clinical trials, which are worth being performed
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