1,369 research outputs found

    PyMT-Maclow: A novel, inducible, murine model for determining the role of CD68 positive cells in breast tumor development

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    CD68+ tumor-associated macrophages (TAMs) are pro-tumorigenic, pro-angiogenic and are associated with decreased survival rates in patients with cancer, including breast cancer. Non-specific models of macrophage ablation reduce the number of TAMs and limit the development of mammary tumors. However, the lack of specificity and side effects associated with these models compromise their reliability. We hypothesized that specific and controlled macrophage depletion would provide precise data on the effects of reducing TAM numbers on tumor development. In this study, the MacLow mouse model of doxycycline-inducible and selective CD68+ macrophage depletion was crossed with the murine mammary tumor virus (MMTV)-Polyoma virus middle T antigen (PyMT) mouse model of spontaneous ductal breast adenocarcinoma to generate the PyMT-MacLow line. In doxycycline-treated PyMT-MacLow mice, macrophage numbers were decreased in areas surrounding tumors by 43%. Reducing the number of macrophages by this level delayed tumor progression, generated less proliferative tumors, decreased the vascularization of carcinomas and down-regulated the expression of many pro-angiogenic genes. These results demonstrate that depleting CD68+ macrophages in an inducible and selective manner delays the development of mammary tumors and that the PyMT-MacLow model is a useful and unique tool for studying the role of TAMs in breast cancer

    The neurodevelopmental implications of hypoplastic left heart syndrome in the fetus

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    Abstract As survival after cardiac surgery continues to improve, an increasing number of patients with hypoplastic left heart syndrome are reaching school age and beyond, with growing recognition of the wide range of neurodevelopmental challenges many survivors face. Improvements in fetal detection rates, coupled with advances in fetal ultrasound and MRI imaging, are contributing to a growing body of evidence that abnormal brain architecture is in fact present before birth in hypoplastic left heart syndrome patients, rather than being solely attributable to postnatal factors. We present an overview of the contemporary data on neurodevelopmental outcomes in hypoplastic left heart syndrome, focussing on imaging techniques that are providing greater insight into the nature of disruptions to the fetal circulation, alterations in cerebral blood flow and substrate delivery, disordered brain development, and an increased potential for neurological injury. These susceptibilities are present before any intervention, and are almost certainly substantial contributors to adverse neurodevelopmental outcomes in later childhood. The task now is to determine which subgroups of patients with hypoplastic left heart syndrome are at particular risk of poor neurodevelopmental outcomes and how that risk might be modified. This will allow for more comprehensive counselling for carers, better-informed decision making before birth, and earlier, more tailored provision of neuroprotective strategies and developmental support in the postnatal period

    Anomalous Aortic Origin of a Coronary Artery With an Interarterial Course Should Family Screening Be Routine?

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    ObjectivesWe sought to present cases of familial occurrence of anomalous aortic origin of a coronary artery with an interarterial course (AAOCA) to determine if it would alter our current screening and management recommendations.BackgroundAnomalous aortic origin of a coronary artery with an interarterial course is a rare congenital anomaly that carries an increased risk of sudden death in children and young adults. There are no reports in the literature of familial AAOCA in the pediatric population.MethodsIn preparation for a multi-institutional prospective study evaluating patient management and surgical outcomes in children and young adults with AAOCA, a questionnaire was sent to multiple pediatric institutions in North and South America. Several respondents indicated caring for families with more than 1 member with AAOCA. These patients were identified and charts were retrospectively reviewed.ResultsWe identified 5 families in which a child was diagnosed with AAOCA and another family member was subsequently identified through screening with echocardiography. The odds of this occurring are significantly greater than what would be expected by chance. All identified by screening were asymptomatic and had anomalous right coronary artery despite 2 of the 5 index cases having anomalous left coronary artery.ConclusionsIt is possible that there is a genetic link for AAOCA. Future research into this is warranted. Due to the potential risk of myocardial ischemia and sudden death associated with AAOCA, screening first-degree relatives for AAOCA using transthoracic echocardiography would be the prudent approach to potentially prevent a sudden catastrophic event

    Pediatric pacemaker infections: Twenty years of experience

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    AbstractObjective: We sought to evaluate possible predictors of early and late pacemaker infections in children. Methods: A review was performed of all pacemakers implanted in children at The Children's Hospital of Philadelphia between 1982 and 2001. Infections were classified as superficial cellulitus, deep pacemaker pocket infection necessitating removal, or positive blood culture without an identifiable source. Results: A total of 385 pacemakers (224 epicardial and 161 endocardial) were implanted in 267 patients at 8.4 ± 6.2 years. All 2141 outpatient visits were reviewed (median follow-up, 29.4 months; range, 2-232 months). There were 30 (7.8%) pacemaker infections: 19 (4.9%) superficial infections; 9 (2.3%) pocket infections; and 2 (0.5%) isolated positive blood cultures. All superficial infections resolved with intravenous antibiotics. The median time from implantation to infection was 16 days (range, 2 days-5 years). Only 1 deep infection occurred after primary pacemaker implantation. Six patients with deep infections were pacemaker dependent and were successfully managed with intravenous antibiotics, followed by lead-generator removal and implantation of a new pacemaker in a remote location. In univariate analyses trisomy 21 (relative risk, 3.9; P <.01), pacemaker revisions (relative risk, 2.5; P <.01), and single-chamber devices (relative risk, 2.4; P <.05) were identified as predictors of infection. However, in multivariate analyses only trisomy 21 and pacemaker revisions were predictors. Conclusions: The incidences of superficial and deep pacemaker infections were 4.9% and 2.3%, respectively. Trisomy 21 and pacemaker revisions were significant risk factors in the development of infection after pacemaker implantation. For primary pacemaker implantation, the risk of infection requiring system removal is low (0.3%).J Thorac Cardiovasc Surg 2002;124:821-

    Successful implementation of stroke early supported discharge services. Collaborative leadership in applied health research and care (CLAHRC), Nottinghamshire, Derbyshire and Lincolnshire, UK

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    A Cochrane systematic review demonstrated that ESD services can reduce long-term dependency and admission to institutional care as well as reducing the length of hospital stay. No adverse impact on the mood or well-being of patients or carers was reported. This ongoing study aims to facilitate and evaluate the successful implementation of Stroke Early Supported Discharge (ESD) services across Nottinghamshire, Derbyshire and Lincolnshire, UK. This study is being conducted to ensure that the health and cost benefits are still in evidence when ESD services are implemented into local areas

    MicroRNA Expression Profiling in Mild Asthmatic Human Airways and Effect of Corticosteroid Therapy

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    BACKGROUND: Asthma is a common disease characterised by reversible airflow obstruction, bronchial hyperresponsiveness and chronic inflammation, which is commonly treated using corticosteroids such as budesonide. MicroRNAs (miRNAs) are a recently identified family of non-protein encoding genes that regulate protein translation by a mechanism entitled RNA interference. Previous studies have shown lung-specific miRNA expression profiles, although their importance in regulating gene expression is unresolved. We determined whether miRNA expression was differentially expressed in mild asthma and the effect of corticosteroid treatment. METHODOLOGY/PRINCIPAL FINDINGS: We have examined changes in miRNA using a highly sensitive RT-PCR based approach to measure the expression of 227 miRNAs in airway biopsies obtained from normal and mild asthmatic patients. We have also determined whether the anti-inflammatory action of corticosteroids are mediated through miRNAs by determining the profile of miRNA expression in mild asthmatics, before and following 1 month twice daily treatment with inhaled budesonide. Furthermore, we have analysed the expression of miRNAs from individual cell populations from the airway and lung. We found no significant difference in the expression of 227 miRNAs in the airway biopsies obtained from normal and mild asthmatic patients. In addition, despite improved lung function, we found no significant difference in the miRNA expression following one month treatment with the corticosteroid, budesonide. However, analysis of bronchial and alveolar epithelial cells, airway smooth muscle cells, alveolar macrophages and lung fibroblasts demonstrate a miRNA expression profile that is specific to individual cell types and demonstrates the complex cellular heterogeneity within whole tissue samples. CONCLUSIONS: Changes in miRNA expression do not appear to be involved in the development of a mild asthmatic phenotype or in the anti-inflammatory action of the corticosteroid budesonid
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