1,455 research outputs found

    Spina bifida

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    Spina bifida is a birth defect in which the vertebral column is open, often with spinal cord involvement. The most clinically significant subtype is myelomeningocele (open spina bifida), which is a condition characterized by failure of the lumbosacral spinal neural tube to close during embryonic development. The exposed neural tissue degenerates in utero, resulting in neurological deficit that varies with the level of the lesion. Occurring in approximately 1 per 1,000 births worldwide, myelomeningocele is one of the most common congenital malformations, but its cause is largely unknown. The genetic component is estimated at 60-70%, but few causative genes have been identified to date, despite much information from mouse models. Non-genetic maternal risk factors include reduced folate intake, anticonvulsant therapy, diabetes mellitus and obesity. Primary prevention by periconceptional supplementation with folic acid has been demonstrated in clinical trials, leading to food fortification programmes in many countries. Prenatal diagnosis is achieved by ultrasonography, enabling women to seek termination of pregnancy. Individuals who survive to birth have their lesions closed surgically, with subsequent management of associated defects, including the Chiari II brain malformation, hydrocephalus, and urological and orthopaedic sequelae. Fetal surgical repair of myelomeningocele has been associated with improved early neurological outcome compared with postnatal operation. Myelomeningocele affects quality of life during childhood, adolescence and adulthood, posing a challenge for individuals, families and society as a whole. For an illustrated summary of this Primer, visit: http://go.nature.com/fK9XNa

    How important is sexual isolation to speciation?

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    K.L.S. was supported by Cornell University and the U.S. NSF during this project. C.R.C was supported by a Natural Environment Research Council Independent Research Fellowship (NE/T01105X/1). T.C.M. is supported by U.S. NSF 2026334. M.G.R. is supported by the Natural Environment Research Council (UK, NE/V001566/1).A central role for sexual isolation in the formation of new species and establishment of species boundaries has been noticed since Darwin and is frequently emphasized in the modern literature on speciation. However, an objective evaluation of when and how sexual isolation plays a role in speciation has been carried out in few taxa. We discuss three approaches for assessing the importance of sexual isolation relative to other reproductive barriers, including the relative evolutionary rate of sexual trait differentiation, the relative strength of sexual isolation in sympatry, and the role of sexual isolation in the long-term persistence of diverging forms. First, we evaluate evidence as to whether sexual isolation evolves faster than other reproductive barriers during the early stages of divergence. Second, we discuss available evidence as to whether sexual isolation is as strong or stronger than other barriers between closely related sympatric species. Finally, we consider the effect of sexual isolation on long-term species persistence, relative to other reproductive barriers. We highlight challenges to our knowledge of and opportunities to improve upon our understanding of sexual isolation from different phases of the speciation process.Peer reviewe

    Expiratory model-based method to monitor ARDS disease state

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    INTRODUCTION: Model-based methods can be used to characterise patient-specific condition and response to mechanical ventilation (MV) during treatment for acute respiratory distress syndrome (ARDS). Conventional metrics of respiratory mechanics are based on inspiration only, neglecting data from the expiration cycle. However, it is hypothesised that expiratory data can be used to determine an alternative metric, offering another means to track patient condition and guide positive end expiratory pressure (PEEP) selection. METHODS: Three fully sedated, oleic acid induced ARDS piglets underwent three experimental phases. Phase 1 was a healthy state recruitment manoeuvre. Phase 2 was a progression from a healthy state to an oleic acid induced ARDS state. Phase 3 was an ARDS state recruitment manoeuvre. The expiratory time-constant model parameter was determined for every breathing cycle for each subject. Trends were compared to estimates of lung elastance determined by means of an end-inspiratory pause method and an integral-based method. All experimental procedures, protocols and the use of data in this study were reviewed and approved by the Ethics Committee of the University of Liege Medical Faculty. RESULTS: The overall median absolute percentage fitting error for the expiratory time-constant model across all three phases was less than 10 %; for each subject, indicating the capability of the model to capture the mechanics of breathing during expiration. Provided the respiratory resistance was constant, the model was able to adequately identify trends and fundamental changes in respiratory mechanics. CONCLUSION: Overall, this is a proof of concept study that shows the potential of continuous monitoring of respiratory mechanics in clinical practice. Respiratory system mechanics vary with disease state development and in response to MV settings. Therefore, titrating PEEP to minimal elastance theoretically results in optimal PEEP selection. Trends matched clinical expectation demonstrating robustness and potential for guiding MV therapy. However, further research is required to confirm the use of such real-time methods in actual ARDS patients, both sedated and spontaneously breathing.Peer reviewe

    The implementation of quality management systems in hospitals: a comparison between three countries

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    BACKGROUND: Is the implementation of Quality Management (QM) in health care proceeding satisfactorily and can national health care policies influence the implementation process? Policymakers and researchers in a country need to know the answer to this question. Cross country comparisons can reveal whether sufficient progress is being made and how this can be stimulated. The objective of the study was to investigate agreement and disparities in the implementation of QMS between The Netherlands, Hungary and Finland with respect to the evaluation model used and the national policy strategy of the three countries. METHODS: The study has a cross sectional design, based on measurements in 2000. Empirical data about QM-activities in hospitals were gathered by a self-administered questionnaire. The questionnaires were answered by the directors of the hospitals or the quality coordinators. The analyses are based on data from 101 hospitals in the Netherlands, 116 hospitals in Hungary and 59 hospitals in Finland. Outcome measures are the developmental stage of the Quality Management System (QMS), the development within five focal areas, and distinct QM-activities which were listed in the questionnaire. RESULTS: A mean of 22 QM-activities per hospital was found in the Netherlands and Finland versus 20 QM-activities in Hungarian hospitals. Only a small number of hospitals has already implemented a QMS (4% in The Netherlands,0% in Hungary and 3% in Finland). More hospitals in the Netherlands are concentrating on quality documents, whereas Finnish hospitals are concentrating on training in QM and guidelines. Cyclic quality improvement activities have been developed in the three countries, but in most hospitals the results were not used for improvements. All three countries pay hardly any attention to patient participation. CONCLUSION: The study demonstrates that the implementation of QM-activities can be measured at national level and that differences between countries can be assessed. The hypothesis that governmental legislation or financial reimbursement can stimulate the implementation of QM-activities, more than voluntary recommendations, could not be confirmed. However, the results show that specific obligations can stimulate the implementation of QM-activities more than general, framework legislation

    Attention deficit hyperactivity symptoms predict problematic mobile phone use

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    Attention-deficit-hyperactivity disorder (ADHD) is the most commonly diagnosed childhood disorder characterised by inattention, hyperactivity/impulsivity, or both. Some of the key traits of ADHD have previously been linked to addictive and problematic behaviours. The aim of the present study was to examine the relationship between problematic mobile phone use, smartphone addiction risk and ADHD symptoms in an adult population. A sample of 273 healthy adult volunteers completed the Adult ADHD Self-Report Scale (ASRS), the Mobile Phone Problem Usage Scale (MPPUS), and the Smartphone Addiction Scale (SAS). A significant positive correlation was found between the ASRS and both scales. More specifically, inattention symptoms and age predicted smartphone addiction risk and problematic mobile phone use. Our results suggest that there is a positive relationship between ADHD traits and problematic mobile phone use. In particular, younger adults with higher level of inattention symptoms could be at higher risk of developing smartphone addiction. The implication of our findings for theoretical frameworks of problematic mobile phone use and clinical practice are discussed

    Hypoxia and oxidative stress in breast cancer: Oxidative stress: its effects on the growth, metastatic potential and response to therapy of breast cancer

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    Reactive oxygen species (ROS) damage DNA, but the role of ROS in breast carcinoma may not be limited to the mutagenic activity that drives carcinoma initiation and progression. Carcinoma cells in vitro and in vivo are frequently under persistent oxidative stress. In the present review, we outline potential causes of oxygen radical generation within carcinoma cells and explore the possible impact of oxidative stress on the clinical outcome of breast carcinoma

    Osseous metaplasia in an ulcerating tubular adenoma of the colon: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Heterotopic bone is rarely found in the gastrointestinal tract. Here we report a rare case of metaplastic ossification within a benign ulcerating adenoma and review the literature concerning the aetiology.</p> <p>Case presentation</p> <p>A 63-year-old woman, who presented with a history of melaena, was found at colonoscopy to have a pedunculated ulcerating polyp. Histological examination demonstrated multiple areas of osseous metaplasia within the polyp stroma.</p> <p>Conclusion</p> <p>Heterotopic ossification in colonic adenomas is a particularly rare phenomenon, with the majority of cases occurring within malignant lesions. The suggested mechanisms for its aetiology still remain unclear.</p

    The conserved C-terminus of the PcrA/UvrD helicase interacts directly with RNA polymerase

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    Copyright: © 2013 Gwynn et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was supported by a Wellcome Trust project grant to MD (Reference: 077368), an ERC starting grant to MD (Acronym: SM-DNA-REPAIR) and a BBSRC project grant to PM, NS and MD (Reference: BB/I003142/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
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