3,591 research outputs found

    Growth trajectories of diploid and tetraploid trees of the Betula pendula/B. pubescens complex (Betulaceae): a 38-year record of trunk circumference

    Get PDF
    Growth in trunk circumference in a natural, uneven-aged stand of 20 trees in the Betula pendula/B. pubescens complex at Holme Fen, Cambridgeshire, UK was monitored over a period of 38 years, from 1977-2014. At the beginning of the study, their chromosome numbers were determined, and trees were aged by counting the rings in radial cores. Circumferential growth trajectories with increasing age of five diploid and 13 tetraploid trees were modelled using three-factor sigmoidal regression. As with previous morphological and molecular studies of the same trees, the tetraploids were considerably more variable in growth trajectory than the diploids; tetraploids included both the slowest- and fastest-growing individuals. Diploids behaved more coherently, having more similar trajectories. Greater variation in tetraploids probably reflects their allopolyploid origin, with subsequent unidirectional introgression. There were indications that diploids may grow faster and reach greater asymptotic circumferences than tetraploids but the differences in this small sample were not statistically significant. There was no evidence that the two cytotypes have different life expectancies

    Oxidative stress-driven parvalbumin interneuron impairment as a common mechanism in models of schizophrenia

    Get PDF
    Parvalbumin inhibitory interneurons (PVIs) are crucial for maintaining proper excitatory/inhibitory balance and high-frequency neuronal synchronization. Their activity supports critical developmental trajectories, sensory and cognitive processing, and social behavior. Despite heterogeneity in the etiology across schizophrenia and autism spectrum disorder, PVI circuits are altered in these psychiatric disorders. Identifying mechanism(s) underlying PVI deficits is essential to establish treatments targeting in particular cognition. On the basis of published and new data, we propose oxidative stress as a common pathological mechanism leading to PVI impairment in schizophrenia and some forms of autism. A series of animal models carrying genetic and/or environmental risks relevant to diverse etiological aspects of these disorders show PVI deficits to be all accompanied by oxidative stress in the anterior cingulate cortex. Specifically, oxidative stress is negatively correlated with the integrity of PVIs and the extracellular perineuronal net enwrapping these interneurons. Oxidative stress may result from dysregulation of systems typically affected in schizophrenia, including glutamatergic, dopaminergic, immune and antioxidant signaling. As convergent end point, redox dysregulation has successfully been targeted to protect PVIs with antioxidants/redox regulators across several animal models. This opens up new perspectives for the use of antioxidant treatments to be applied to at-risk individuals, in close temporal proximity to environmental impacts known to induce oxidative stress

    Novel Prognostic Markers in Triple-Negative Breast Cancer Discovered by MALDI-Mass Spectrometry Imaging

    Get PDF
    There are no widely-accepted prognostic markers currently available to predict outcomes in patients with triple-negative breast cancer (TNBC), and no targeted therapies with confirmed benefit. We have used MALDI mass spectrometry imaging (MSI) of tryptic peptides to compare regions of cancer and benign tissue in 10 formalin-fixed, paraffin-embedded sections of TNBC tumors. Proteins were identified by reference to a peptide library constructed by LC-MALDI-MS/MS analyses of the same tissues. The prognostic significance of proteins that distinguished between cancer and benign regions was estimated by Kaplan-Meier analysis of their gene expression from public databases. Among peptides that distinguished between cancer and benign tissue in at least 3 tissues with a ROC area under the curve >0.7, 14 represented proteins identified from the reference library, including proteins not previously associated with breast cancer. Initial network analysis using the STRING database showed no obvious functional relationships except among collagen subunits COL1A1, COL1A2, and COL63A, but manual curation, including the addition of EGFR to the analysis, revealed a unique network connecting 10 of the 14 proteins. Kaplan-Meier survival analysis to examine the relationship between tumor expression of genes encoding the 14 proteins, and recurrence-free survival (RFS) in patients with basal-like TNBC showed that, compared to low expression, high expression of nine of the genes was associated with significantly worse RFS, most with hazard ratios >2. In contrast, in estrogen receptor-positive tumors, high expression of these genes showed only low, or no, association with worse RFS. These proteins are proposed as putative markers of RFS in TNBC, and some may also be considered as possible targets for future therapies

    Accuracy of prospective two-dimensional/Doppler echocardiography in the assessment of reparative surgery

    Get PDF
    Between January 1987 and January 1989, all 129 patients (aged 11 days to 25 years, median 39 months) undergoing both an echocardiographic examination and cardiac catheterization after reparative surgery were prospectively included in a study to assess the accuracy of combined two-dimensional and Doppler color flow imaging. The patient diagnoses were transposition of the great arteries (n = 20), tetralogy of Fallot (n = 38), coarctation of the aorta (n = 24), complete atrioventricular (AV) canal (n = 15), atrial septal defect (n = 8), ventricular septal defects (n = 3), pulmonary stenosis (n = 4), aortic stenosis (n = 8) and subaortic stenosis (n = 9).In arterial tract stenosis, there was high correlation between Doppler estimates and catheterization-derived measurements of residual right ventricular outflow tract obstruction in patients after the arterial switch operation for transposition of the great arteries (r = 0.95) as well as in patients after corrective repair of tetralogy of Fallot (r = 0.84).In semilunar/AV valve regurgitation, graded as none, mild, moderate or severe, echocardiographic estimates correlated exactly with angiographic grading in 84% and differed by one angiographic grade in the other 16%.In residual left to right shunting, no hemodynamically significant shunt was missed by echocardiography. For residual shunts at the ventricular level (n = 32), addition of Doppler color flow imaging improved the sensitivity (from 63% to 94%) and the negative predictive value (from 88% to 98%).In elevated right ventricular pressure, Doppler-derived right ventricular-right atrial pressure estimates in 24 patients correlated well with catheterization measurements (r = 0.93).Combined two-dimensional and Doppler color flow echocardiography was highly accurate in the prospective evaluation of these four types of postoperative residua

    Multivisceral resection of pancreatic neuroendocrine tumours: a report of two cases

    Get PDF
    Pancreatic neuroendocrine tumours (pNETs) are rare and surgical resection offers the only possibility of cure for localised disease. The role of surgery in the setting of locally advanced and metastatic disease is more controversial. Emerging data suggests that synchronous surgical resection of pancreas and liver may be associated with increased survival. We report two cases of synchronous, one stage multivisceral resections for pNET and associated reconstruction. We highlight the technical issues involved in such extensive resections and demonstrate that one stage multivisceral operations can be achieved safely

    The Evidence Base for Interventions Delivered to Children in Primary Care: An Overview of Cochrane Systematic Reviews

    Get PDF
    Background: As a first step in developing a framework to evaluate and improve the quality of care of children in primary care there is a need to identify the evidence base underpinning interventions relevant to child health. Our objective was to identify all Cochrane systematic reviews relevant to the management of childhood conditions in primary care and to assess the extent to which Cochrane reviews reflect the burden of childhood illness presenting in primary care.Methodology/Principal Findings: We used the Cochrane Child Health Field register of child-relevant systematic reviews to complete an overview of Cochrane reviews related to the management of children in primary care. We compared the proportion of systematic reviews with the proportion of consultations in Australia, US, Dutch and UK general practice in children. We identified 396 relevant systematic reviews; 385 included primary studies on children while 251 undertook a meta-analysis. Most reviews (n=218, 55%) focused on chronic conditions and over half (n=216, 57%) evaluated drug interventions. Since 2000, the percentage of pediatric primary care relevant reviews only increased by 2% (7% to 9%) compared to 18% (10% to 28%) in all child relevant reviews. Almost a quarter of reviews (n=78, 23%) were published on asthma treatments which only account for 3-5% of consultations. Conversely, 15-23% of consultations are due to skin conditions yet they represent only 7% (n=23) of reviews.Conclusions/Significance: Although Cochrane systematic reviews focus on clinical trials and do not provide a comprehensive picture of the evidence base underpinning the management of children in primary care, the mismatch between the focus of the published research and the focus of clinical activity is striking. Clinical trials are an important component of the evidence based and the lack of trial evidence to demonstrate intervention effectiveness in substantial areas of primary care for children should be addressed.</p

    Pregnant and Postpartum Women’s Experiences and Perspectives on the Acceptability and Feasibility of Copackaged Medicine for Antenatal Care and PMTCT in Lesotho

    Get PDF
    Objective. To improve PMTCT and antenatal care-related service delivery, a pack with centrally prepackaged medicine was rolled out to all pregnant women in Lesotho in 2011. This study assessed acceptability and feasibility of this copackaging mechanism for drug delivery among pregnant and postpartum women. Methods. Acceptability and feasibility were assessed in a mixed method, cross-sectional study through structured interviews (SI) and semistructured interviews (SSI) conducted in 2012 and 2013. Results. 290 HIV-negative women and 437 HIV-positive women (n=727) participated. Nearly all SI participants found prepackaged medicines acceptable, though modifications such as size reduction of the pack were suggested. Positive experiences included that the pack helped women take pills as instructed and contents promoted healthy pregnancies. Negative experiences included inadvertent pregnancy disclosure and discomfort carrying the pack in communities. Implementation was also feasible; 85.2% of SI participants reported adequate counseling time, though 37.8% felt pack use caused clinic delays. SSI participants reported improvement in service quality following pack introduction, due to more comprehensive counseling. Conclusions. A prepackaged drug delivery mechanism for ANC/PMTCT medicines was acceptable and feasible. Findings support continued use of this approach in Lesotho with improved design modifications to reflect the current PMTCT program of lifelong treatment for all HIV-positive pregnant women

    Il monastero benedettino di S. Giorgio in Braida a Verona: nuove prospettive di ricerca sulla rifabbrica romanica (sec. XII)

    Get PDF
    L’attuale aspetto rinascimentale della chiesa di San Giorgio in Braida è frutto di una serie di interventi promossi dai canonici veneziani di San Giorgio in Alga a partire dalla fine del XV secolo. Il monastero benedettino, tuttavia, fu fondato nella metà dell’XI secolo e completamente ricostruito fra il terzo e il quarto decennio del secolo successivo per volere del vescovo Bernardo. L’articolo ripercorre le vicende storiche dell’istituzione in età medievale e rende nota l’esistenza di alcune parti della compagine romanica tuttora inedite, che permettono d’inserire il cantiere di San Giorgio in Braida nel contesto delle coeve manifestazioni architettoniche veronesi
    • …
    corecore