157 research outputs found

    Addressing resistance to antibiotics in systematic reviews of antibiotic interventions

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    Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should be reported and taken into account when interpreting results. Data on emergence of resistance (whether in the body reservoirs or in the bacteria causing infection) are important outcomes. Emergence of resistance should be taken into account when interpreting the evidence on antibiotic treatment in randomized controlled trials or systematic reviews

    Some Like It Fat: Comparative Ultrastructure of the Embryo in Two Demosponges of the Genus Mycale (Order Poecilosclerida) from Antarctica and the Caribbean

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    0000-0002-7993-1523© 2015 Riesgo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License [4.0], which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article

    Galectin-1 as a potential cancer target

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    Galectins are a family of structurally related carbohydrate-binding proteins, which are defined by their affinity for poly-N-acetyllactosamine-enriched glycoconjugates and sequence similarities in the carbohydrate recognition domain. Galectin-1, a member of this family, contributes to different events associated with cancer biology, including tumour transformation, cell cycle regulation, apoptosis, cell adhesion, migration and inflammation. In addition, recent evidence indicates that galectin-1 contributes to tumour evasion of immune responses. Given the increased interest of tumour biologists and clinical oncologists in this field and the potential use of galectins as novel targets for anticancer drugs, we summarise here recent advances about the role of galectin-1 in different events of tumour growth and metastasis

    AKAP95 regulates splicing through scaffolding RNAs and RNA processing factors

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    YesAlternative splicing of pre-mRNAs significantly contributes to the complexity of gene expression in higher organisms, but the regulation of the splice site selection remains incompletely understood. We have previously demonstrated that a chromatin-associated protein, AKAP95 (AKAP8), has a remarkable activity in enhancing chromatin transcription. In this study, we have shown that AKAP95 physically interacts with many factors involved in transcription and RNA processing, and functionally regulates pre-mRNA splicing. AKAP95 directly promotes splicing in vitro and the inclusion of a specific exon of an endogenous gene FAM126A. The N-terminal YG-rich domain of AKAP95 is important for its binding to RNA processing factors including selective groups of hnRNP proteins, and its zinc finger domains are critical for pre-mRNA binding. Genome-wide binding assays revealed that AKAP95 bound preferentially to proximal intronic regions on a large number of pre-mRNAs in human transcriptome, and AKAP95 depletion predominantly resulted in reduced inclusion of many exons. AKAP95 also selectively coordinates with hnRNP H/F and U proteins in regulating alternative splicing events. We have further shown that AKAP95 directly interacts with itself. Taken together, our results establish AKAP95 as a novel and mostly positive regulator of premRNA splicing and a possible integrator of transcription and splicing regulation, and support a model that AKAP95 facilitates the splice site communication by looping out introns through both RNA-binding and protein-protein interaction.This work was supported by a UAB start-up fund to H.J

    Single Molecule PCR Reveals Similar Patterns of Non-Homologous DSB Repair in Tobacco and Arabidopsis

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    DNA double strand breaks (DSBs) occur constantly in eukaryotes. These potentially lethal DNA lesions are repaired efficiently by two major DSB repair pathways: homologous recombination and non-homologous end joining (NHEJ). We investigated NHEJ in Arabidopsis thaliana and tobacco (Nicotiana tabacum) by introducing DNA double-strand breaks through inducible expression of I-SceI, followed by amplification of individual repair junction sequences by single-molecule PCR. Using this process over 300 NHEJ repair junctions were analysed in each species. In contrast to previously published variation in DSB repair between Arabidopsis and tobacco, the two species displayed similar DSB repair profiles in our experiments. The majority of repair events resulted in no loss of sequence and small (1–20 bp) deletions occurred at a minority (25–45%) of repair junctions. Approximately ∼1.5% of the observed repair events contained larger deletions (>20 bp) and a similar percentage contained insertions. Strikingly, insertion events in tobacco were associated with large genomic deletions at the site of the DSB that resulted in increased micro-homology at the sequence junctions suggesting the involvement of a non-classical NHEJ repair pathway. The generation of DSBs through inducible expression of I-SceI, in combination with single molecule PCR, provides an effective and efficient method for analysis of individual repair junctions and will prove a useful tool in the analysis of NHEJ

    Estrogen receptor transcription and transactivation: Estrogen receptor alpha and estrogen receptor beta - regulation by selective estrogen receptor modulators and importance in breast cancer

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    Estrogens display intriguing tissue-selective action that is of great biomedical importance in the development of optimal therapeutics for the prevention and treatment of breast cancer, for menopausal hormone replacement, and for fertility regulation. Certain compounds that act through the estrogen receptor (ER), now referred to as selective estrogen receptor modulators (SERMs), can demonstrate remarkable differences in activity in the various estrogen target tissues, functioning as agonists in some tissues but as antagonists in others. Recent advances elucidating the tripartite nature of the biochemical and molecular actions of estrogens provide a good basis for understanding these tissue-selective actions. As discussed in this thematic review, the development of optimal SERMs should now be viewed in the context of two estrogen receptor subtypes, ERα and ERβ, that have differing affinities and responsiveness to various SERMs, and differing tissue distribution and effectiveness at various gene regulatory sites. Cellular, biochemical, and structural approaches have also shown that the nature of the ligand affects the conformation assumed by the ER-ligand complex, thereby regulating its state of phosphorylation and the recruitment of different coregulator proteins. Growth factors and protein kinases that control the phosphorylation state of the complex also regulate the bioactivity of the ER. These interactions and changes determine the magnitude of the transcriptional response and the potency of different SERMs. As these critical components are becoming increasingly well defined, they provide a sound basis for the development of novel SERMs with optimal profiles of tissue selectivity as medical therapeutic agents

    Bacterial laccases: some recent advances and applications

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    Laccases belong to the large family of multi-copper oxidases (MCOs) that couple the one-electron oxidation of substrates with the four-electron reduction of molecular oxygen to water. Because of their high relative non-specific oxidation capacity particularly on phenols and aromatic amines as well as the lack of requirement for expensive organic cofactors, they have found application in a large number of biotechnological fields. The vast majority of studies and applications were performed using fungal laccases, but bacterial laccases show interesting properties such as optimal temperature above 50 °C, optimal pH at the neutral to alkaline range, thermal and chemical stability and increased salt tolerance. Additionally, bacterial systems benefit from a wide range of molecular biology tools that facilitates their engineering and achievement of high yields of protein production and set-up of cost-effective bioprocesses. In this review we will provide up-to-date information on the distribution and putative physiological role of bacterial laccases and highlight their distinctive structural and biochemical properties, discuss the key role of copper in the biochemical properties, discuss thermostability determinants and, finally, review biotechnological applications with a focus on catalytic mechanisms on phenolics and aromatic amines.info:eu-repo/semantics/publishedVersio

    Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK): Explanation and Elaboration

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    The REMARK “elaboration and explanation” guideline, by Doug Altman and colleagues, provides a detailed reference for authors on important issues to consider when designing, conducting, and analyzing tumor marker prognostic studies

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
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