500 research outputs found

    High contiguity genome sequence of a multidrug-resistant hospital isolate of Enterobacter hormaechei

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    © 2019 The Author(s). Background: Enterobacter hormaechei is an important emerging pathogen and a key member of the highly diverse Enterobacter cloacae complex. E. hormaechei strains can persist and spread in nosocomial environments, and often exhibit resistance to multiple clinically important antibiotics. However, the genomic regions that harbour resistance determinants are typically highly repetitive and impossible to resolve with standard short-read sequencing technologies. Results: Here we used both short- and long-read methods to sequence the genome of a multidrug-resistant hospital isolate (C15117), which we identified as E. hormaechei. Hybrid assembly generated a complete circular chromosome of 4,739,272 bp and a fully resolved plasmid of 339,920 bp containing several antibiotic resistance genes. The strain also harboured a 34,857 bp repeat encoding copper resistance, which was present in both the chromosome and plasmid. Long reads that unambiguously spanned this repeat were required to resolve the chromosome and plasmid into separate replicons. Conclusion: This study provides important insights into the evolution and potential spread of antimicrobial resistance in a nosocomial E. hormaechei strain. More broadly, it further exemplifies the power of long-read sequencing technologies, particularly the Oxford Nanopore platform, for the characterisation of bacteria with complex resistance loci and large repeat elements

    How are "teaching the teachers" courses in evidence based medicine evaluated? A systematic review

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    Background Teaching of evidence-based medicine (EBM) has become widespread in medical education. Teaching the teachers (TTT) courses address the increased teaching demand and the need to improve effectiveness of EBM teaching. We conducted a systematic review of assessment tools for EBM TTT courses. To summarise and appraise existing assessment methods for teaching the teachers courses in EBM by a systematic review. Methods We searched PubMed, BioMed, EmBase, Cochrane and Eric databases without language restrictions and included articles that assessed its participants. Study selection and data extraction were conducted independently by two reviewers. Results Of 1230 potentially relevant studies, five papers met the selection criteria. There were no specific assessment tools for evaluating effectiveness of EBM TTT courses. Some of the material available might be useful in initiating the development of such an assessment tool. Conclusion There is a need for the development of educationally sound assessment tools for teaching the teachers courses in EBM, without which it would be impossible to ascertain if such courses have the desired effect

    Fast-growing pancreatic neuroendocrine carcinoma in a patient with multiple endocrine neoplasia type 1: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Predictive genetic screening and regular screening programs in patients with multiple endocrine neoplasia type 1 are intended to detect and treat malignant tumors at the earliest stage possible. Malignant neuroendocrine pancreatic tumors are the most frequent cause of death in these patients. However, the extent and intervals of screening in patients with multiple endocrine neoplasia type 1 are controversial as neuroendocrine tumors are usually slow growing. Here we report the case of a patient who developed a fast-growing neuroendocrine carcinoma within 15 months of a laparoscopic distal pancreatic resection.</p> <p>Case presentation</p> <p>We followed a group of 45 patients with multiple endocrine neoplasia type 1 by an annual screening program in the Department of Visceral, Thoracic, and Vascular Surgery at the University Hospital Marburg in cooperation with the Department of Radiology and the Division of Endocrinology. A man with multiple endocrine neoplasia type 1 who was diagnosed with a recurrent primary hyperparathyroidism underwent a distal pancreatic resection for a non-functional neuroendocrine tumor. In the context of our regular screening program, a large non-functional neuroendocrine tumor was diagnosed in the pancreatic head 15 months after the first pancreatic surgery. Therefore, we performed an enucleation and regional lymph node resection. At histology, the diagnosis of a neuroendocrine carcinoma with one lymph node metastasis was established. There was no evidence of recurrence 9 months after re-operation.</p> <p>Conclusion</p> <p>Fast-growing neuroendocrine tumors are rare in patients with multiple endocrine neoplasia type 1. The intervals, both postoperative and in newly diagnosed pancreatic lesions, in patients with multiple endocrine neoplasia type 1 should be reduced to 6 months to establish the early diagnosis of rapidly progressive disease in a small subset of patients.</p

    Differences in genotype and virulence among four multidrug-resistant <i>Streptococcus pneumoniae</i> isolates belonging to the PMEN1 clone

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    We report on the comparative genomics and characterization of the virulence phenotypes of four &lt;i&gt;S. pneumoniae&lt;/i&gt; strains that belong to the multidrug resistant clone PMEN1 (Spain&lt;sup&gt;23F&lt;/sup&gt; ST81). Strains SV35-T23 and SV36-T3 were recovered in 1996 from the nasopharynx of patients at an AIDS hospice in New York. Strain SV36-T3 expressed capsule type 3 which is unusual for this clone and represents the product of an in vivo capsular switch event. A third PMEN1 isolate - PN4595-T23 - was recovered in 1996 from the nasopharynx of a child attending day care in Portugal, and a fourth strain - ATCC700669 - was originally isolated from a patient with pneumococcal disease in Spain in 1984. We compared the genomes among four PMEN1 strains and 47 previously sequenced pneumococcal isolates for gene possession differences and allelic variations within core genes. In contrast to the 47 strains - representing a variety of clonal types - the four PMEN1 strains grouped closely together, demonstrating high genomic conservation within this lineage relative to the rest of the species. In the four PMEN1 strains allelic and gene possession differences were clustered into 18 genomic regions including the capsule, the blp bacteriocins, erythromycin resistance, the MM1-2008 prophage and multiple cell wall anchored proteins. In spite of their genomic similarity, the high resolution chinchilla model was able to detect variations in virulence properties of the PMEN1 strains highlighting how small genic or allelic variation can lead to significant changes in pathogenicity and making this set of strains ideal for the identification of novel virulence determinant

    Adolescent gambling behaviour, a single latent construct and indicators of risk: findings from a national survey of New Zealand high school students

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    This study explores underlying latent construct/s of gambling behaviour, and identifies indicators of “unhealthy gambling”. Data were collected from Youth’07 a nationally representative sample of New Zealand secondary school students (N = 9107). Exploratory factor analyses, item-response theory analyses, multiple indicators-multiple causes, and differential item functioning analyses were used to assess dimensionality of gambling behaviour, underlying factors, and indicators of unhealthy gambling. A single underlying continuum of gambling behaviour was identified. Gambling frequency and ‘gambling because I can’t stop’ were most strongly associated with unhealthy gambling. Gambling to ‘feel better about myself’ and to ‘forget about things’ provided the most precise discriminants of unhealthy gambling. Multivariable analyses found that school connectedness was associated with lower levels of unhealthy gambling

    27 years of benthic and coral community dynamics on turbid, highly urbanised reefs off Singapore

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    Coral cover on reefs is declining globally due to coastal development, overfishing and climate change. Reefs isolated from direct human influence can recover from natural acute disturbances, but little is known about long term recovery of reefs experiencing chronic human disturbances. Here we investigate responses to acute bleaching disturbances on turbid reefs off Singapore, at two depths over a period of 27 years. Coral cover declined and there were marked changes in coral and benthic community structure during the first decade of monitoring at both depths. At shallower reef crest sites (3–4 m), benthic community structure recovered towards pre-disturbance states within a decade. In contrast, there was a net decline in coral cover and continuing shifts in community structure at deeper reef slope sites (6–7 m). There was no evidence of phase shifts to macroalgal dominance but coral habitats at deeper sites were replaced by unstable substrata such as fine sediments and rubble. The persistence of coral dominance at chronically disturbed shallow sites is likely due to an abundance of coral taxa which are tolerant to environmental stress. In addition, high turbidity may interact antagonistically with other disturbances to reduce the impact of thermal stress and limit macroalgal growth rates

    Stereotactically guided breast biopsy: a review

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    The aims of this review are to compare and contrast the available stereotactic equipment, and to describe the variety of needle types used and their affect on pathological results and subsequent patient management. Initial stereotactic devices were “added-on” to analogue mammography units and have been replaced by prone or ducubitus equipment using digital image acquisition. Biopsies use either 14-G core biopsy (CB) needles or vacuum-assisted biopsies (VAB). Vacuum-assisted biopsy systems consistently out-perform 14-G CB with reduced need for diagnostic or multi-treatment surgery. The false-negative rate is 8% for 14-G CB compared with 0.7% for VAB. There is a risk of underestimating the disease present for lesions of uncertain malignant potential (Cat B3) and suspicious of malignancy (Cat B4) results with 25% of patients with a B3 biopsy found to have cancer at subsequent surgery and 66% of those with a B4 biopsy. A CB diagnosis of in situ malignancy is upgraded to invasive disease at surgery in 15-36% of patients undergoing CB and of the order of 10% with VAB. A high degree of diagnostic accuracy and hence safe patient care can only be achieved by meticulous attention to technique and multi-disciplinary cooperation

    Fluid flow in the osteocyte mechanical environment : a fluid-structure interaction approach

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    Osteocytes are believed to be the primary sensor of mechanical stimuli in bone, which orchestrate osteoblasts and osteoclasts to adapt bone structure and composition to meet physiological loading demands. Experimental studies to quantify the mechanical environment surrounding bone cells are challenging, and as such, computational and theoretical approaches have modelled either the solid or fluid environment of osteocytes to predict how these cells are stimulated in vivo. Osteocytes are an elastic cellular structure that deforms in response to the external fluid flow imposed by mechanical loading. This represents a most challenging multi-physics problem in which fluid and solid domains interact, and as such, no previous study has accounted for this complex behaviour. The objective of this study is to employ fluid–structure interaction (FSI) modelling to investigate the complex mechanical environment of osteocytes in vivo. Fluorescent staining of osteocytes was performed in order to visualise their native environment and develop geometrically accurate models of the osteocyte in vivo. By simulating loading levels representative of vigorous physiological activity (3,000με compression and 300 Pa pressure gradient), we predict average interstitial fluid velocities (∼60.5μ m/s ) and average maximum shear stresses (∼11 Pa ) surrounding osteocytes in vivo. Interestingly, these values occur in the canaliculi around the osteocyte cell processes and are within the range of stimuli known to stimulate osteogenic responses by osteoblastic cells in vitro. Significantly our results suggest that the greatest mechanical stimulation of the osteocyte occurs in the cell processes, which, cell culture studies have indicated, is the most mechanosensitive area of the cell. These are the first computational FSI models to simulate the complex multi-physics mechanical environment of osteocyte in vivo and provide a deeper understanding of bone mechanobiology
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