305 research outputs found

    Bayesian Wavelet Shrinkage of the Haar-Fisz Transformed Wavelet Periodogram.

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    It is increasingly being realised that many real world time series are not stationary and exhibit evolving second-order autocovariance or spectral structure. This article introduces a Bayesian approach for modelling the evolving wavelet spectrum of a locally stationary wavelet time series. Our new method works by combining the advantages of a Haar-Fisz transformed spectrum with a simple, but powerful, Bayesian wavelet shrinkage method. Our new method produces excellent and stable spectral estimates and this is demonstrated via simulated data and on differenced infant electrocardiogram data. A major additional benefit of the Bayesian paradigm is that we obtain rigorous and useful credible intervals of the evolving spectral structure. We show how the Bayesian credible intervals provide extra insight into the infant electrocardiogram data

    Primary right atrium angiosarcoma mimicking pericarditis

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    <p>Abstract</p> <p>Background</p> <p>Primary cardiac neoplasms occur rarely and most of them are benign. Malignant tumors including angiosarcoma are extremely rare and have a non specific clinical presentation and a poor prognosis.</p> <p>Case presentation</p> <p>We present a case of a young male who was transferred to our hospital because of shock and multiple organ failure after a complicated pericardial biopsy. During the previous seven months he presented with recurrent episodes of pericardial effusions and tamponade. Chest computed tomography revealed a mass in the right atrium, infiltrating the myocardium and pericardium. During emergency surgery that followed, the patient died because of uncontrolled hemorrhage. Autopsy revealed the mass of the right atrium, which was identified on histological examination as primary cardiac angiosarcoma.</p> <p>Conclusion</p> <p>This case highlights the difficulties both in early diagnosis and in the management of patients with cardiac angiosarcoma.</p

    Prescription of respiratory medication without an asthma diagnosis in children: a population based study

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    Background. In pre-school children a diagnosis of asthma is not easily made and only a minority of wheezing children will develop persistent atopic asthma. According to the general consensus a diagnosis of asthma becomes more certain with increasing age. Therefore the congruence between asthma medication use and doctor-diagnosed asthma is expected to increase with age. The aim of this study is to evaluate the relationship between prescribing of asthma medication and doctor-diagnosed asthma in children age 0-17. Methods. We studied all 74,580 children below 18 years of age, belonging to 95 GP practices within the second Dutch national survey of general practice (DNSGP-2), in which GPs registered all physician-patient contacts during the year 2001. Status on prescribing of asthma medication (at least one prescription for beta2-agonists, inhaled corticosteroids, cromones or montelukast) and doctor-diagnosed asthma (coded according to the International Classification of Primary Care) was determined. Results. In total 7.5% of children received asthma medication and 4.1% had a diagnosis of asthma. Only 49% of all children receiving asthma medication was diagnosed as an asthmatic. Subgroup analyses on age, gender and therapy groups showed that the Positive Predictive Value (PPV) differs significantly between therapy groups only. The likelihood of having doctor-diagnosed asthma increased when a child received combination therapy of short acting beta2-agonists and inhaled corticosteroids (PPV = 0.64) and with the number of prescriptions (3 prescriptions or more, PPV = 0.66). Both prescribing of asthma medication and doctor-diagnosed asthma declined with age but the congruence between the two measures did not increase with age. Conclusion. In this study, less than half of all children receiving asthma medication had a registered diagnosis of asthma. Detailed subgroup analyses show that a diagnosis of asthma was present in at most 66%, even in groups of children treated intensively with asthma medication. Although age strongly influences the chance of being treated, remarkably, the congruence between prescribing of asthma medication and doctor-diagnosed asthma does not increase with age

    Reconnection dynamics and mutual friction in quantum turbulence

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    We investigate the behaviour of the mutual friction force in finite temperature quantum turbulence in 4He, paying particular attention to the role of quantized vortex reconnections. Through the use of the vortex filament model, we produce three experimentally relevant types of vortex tangles in steady-state conditions, and examine through statistical analysis, how local properties of the tangle influence the mutual friction force. Finally, by monitoring reconnection events, we present evidence to indicate that vortex reconnections are the dominant mechanism for producing areas of high curvature and velocity leading to regions of high mutual friction, particularly for homogeneous and isotropic vortex tangles

    Understanding atrioventricular septal defect: Anatomoechocardiographic correlation

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    <p>Abstract</p> <p>Objective</p> <p>Correlate the anatomic features of atrioventricular septal defect with echocardiographic images.</p> <p>Materials and methods</p> <p>Sixty specimen hearts were studied by sequential segmental analysis. Echocardiograms were performed on 34 patients. Specimen hearts with findings equivalent to those of echocardiographic images were selected in order to establish an anatomo-echocardiographic correlation.</p> <p>Results</p> <p>Thirty-three specimen hearts were in situs solitus, 19 showed dextroisomerism, 6 were in situs inversus and 2 levoisomerism. Fifty-eight had a common atrioventricular valve and 2 had two atrioventricular valves. Rastelli types were determined in 21 hearts. Nine were type A, 2 intermediate between A and B, 1 mixed between A and B, 4 type B and 5 type C. Associated anomalies included pulmonary stenosis, pulmonary atresia atrial septal defect, patent ductus arteriosus and anomalous connection of pulmonary veins. Echocardiograms revealed dextroisomerism in 12 patients, situs solitus in 11, levoisomerism in 7 and situs inversus in 4. Thirty-one patients had common atrioventricular valves and three two atrioventricular valves. Rastelli types were established in all cases with common atrioventricular valves; 17 had type A canal defects, 10 type B, 3 intermediate between A and B, 1 mixed between A and B and 3 type C. Associated anomalies included regurgitation of the atrioventricular valve, pulmonary stenosis, anomalous connection of pulmonary veins, pulmonary hypertension and pulmonary atresia.</p> <p>Conclusion</p> <p>Anatomo-echocardiographic correlation demonstrated a high degree of diagnostic precision with echocardiography.</p

    Neuroinflammation, Mast Cells, and Glia: Dangerous Liaisons

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    The perspective of neuroinflammation as an epiphenomenon following neuron damage is being replaced by the awareness of glia and their importance in neural functions and disorders. Systemic inflammation generates signals that communicate with the brain and leads to changes in metabolism and behavior, with microglia assuming a pro-inflammatory phenotype. Identification of potential peripheral-to-central cellular links is thus a critical step in designing effective therapeutics. Mast cells may fulfill such a role. These resident immune cells are found close to and within peripheral nerves and in brain parenchyma/meninges, where they exercise a key role in orchestrating the inflammatory process from initiation through chronic activation. Mast cells and glia engage in crosstalk that contributes to accelerate disease progression; such interactions become exaggerated with aging and increased cell sensitivity to stress. Emerging evidence for oligodendrocytes, independent of myelin and support of axonal integrity, points to their having strong immune functions, innate immune receptor expression, and production/response to chemokines and cytokines that modulate immune responses in the central nervous system while engaging in crosstalk with microglia and astrocytes. In this review, we summarize the findings related to our understanding of the biology and cellular signaling mechanisms of neuroinflammation, with emphasis on mast cell-glia interactions

    Evaluation of high-dose daptomycin for therapy of experimental Staphylococcus aureus foreign body infection

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    BACKGROUND: Daptomycin is a novel cyclic lipopeptide whose bactericidal activity is not affected by current antibiotic resistance mechanisms displayed by S. aureus clinical isolates. This study reports the therapeutic activity of high-dose daptomycin compared to standard regimens of oxacillin and vancomycin in a difficult-to-treat, rat tissue cage model of experimental therapy of chronic S. aureus foreign body infection. METHODS: The methicillin-susceptible S. aureus (MSSA) strain I20 is a clinical isolate from catheter-related sepsis. MICs, MBCs, and time-kill curves of each antibiotic were evaluated as recommended by NCCLS, including supplementation with physiological levels (50 mg/L) of Ca(2+ )for daptomycin. Two weeks after local infection of subcutaneously implanted tissue cages with MSSA I20, each animal received (i.p.) twice-daily doses of daptomycin, oxacillin, or vancomycin for 7 days, or was left untreated. The reductions of CFU counts in each treatment group were analysed by ANOVA and Newman-Keuls multiple comparisons procedures. RESULTS: The MICs and MBCs of daptomycin, oxacillin, or vancomycin for MSSA strain I20 were 0.5 and 1, 0.5 and 1, or 1 and 2 mg/L, respectively. In vitro elimination of strain I20 was more rapid with 8 mg/L of daptomycin compared to oxacillin or vancomycin. Twice-daily administered daptomycin (30 mg/kg), oxacillin (200 mg/kg), or vancomycin (50 mg/kg vancomycin) yielded bactericidal antibiotic levels in infected cage fluids throughout therapy. Before therapy, mean (± SEM) viable counts of strain I20 were 6.68 ± 0.10 log(10 )CFU/mL of cage fluid (n = 74). After 7 days of therapy, the mean (± SEM) reduction in viable counts of MSSA I20 was 2.62 (± 0.30) log(10 )CFU/mL in cages (n = 18) of daptomycin-treated rats, exceeding by >2-fold (P < 0.01) the viable count reductions of 0.92 (± 0.23; n = 19) and 0.96 (± 0.24; n = 18) log(10 )CFU/mL in cages of oxacillin-treated and vancomycin-treated rats, respectively. Viable counts in cage fluids of untreated animals increased by 0.48 (± 0.24; n = 19) log(10 )CFU/mL. CONCLUSION: The improved efficacy of the twice-daily regimen of daptomycin (30 mg/kg) compared to oxacillin (200 mg/kg) or vancomycin (50 mg/kg) may result from optimisation of its pharmacokinetic and bactericidal properties in infected cage fluids

    The course of the acute vertebral body fragility fracture: its effect on pain, disability and quality of life during 12 months

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    The vertebral body fracture is the most frequent bone fragility fracture. In spite of this there is considerable uncertainty about the frequency, extent and severity of the acute pain and even more about the duration of pain, the magnitude of disability and how much daily life is disturbed in the post-fracture period. The aim of the present study was to follow the course of pain, disability, ADL and QoL in patients during the year after an acute low energy vertebral body fracture. The study design was a longitudinal cohort study with prospective data collection. All the patients over 40 years admitted to the emergency unit because of back pain with a radiologically acute vertebral body fracture were eligible. A total of 107 patients were followed for a year. The pain, disability (von Korff pain and disability scores), ADL (Hannover ADL score), and QoL (EQ-5D) were measured after 3 weeks, 3, 6 and 12 months. Two-thirds of the patients were women, and were similar in average age, as the men around 75 years. A total of 65.4% of the fractures were due to a level fall or a minor trauma, whereas 34.6% had no recollection of trauma or a specific event as the cause of the fracture. A total of 76.6% of the fractured patients were immediately mobilized and allowed to return home while the remaining were hospitalized. The average pain intensity score after 3 weeks was 70.9 (SD 19.3), the disability score 68.9 (SD 23.6), the ADL score 37.7 (SD 22.1) and EQ-5D score of 0.37 (SD 0.37). The largest improvements, 10–15%, occurred between the initial visit and the 3 months follow-up and were quite similar for all the measures. From 3 months, all the outcome measures leveled out or tended to deteriorate resulting in a mean pain intensity score of 60.5, disability score of 53.9, ADL score of 47.6, and EQ-5D score 0.52 after 12 months. After a whole year the fractured patients’ condition was similar to the preoperative condition of patients with a herniated lumbar disc, central lumbar spinal stenosis or in patients 100% work disabled due to back or neck problems. Instead of the generally believed good prognosis for the greater majority of those fractured, the acute vertebral body fracture was the beginning of a long-lasting severe deterioration of their health

    Increased Expression of Beta-Defensin 1 (DEFB1) in Chronic Obstructive Pulmonary Disease

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    On-going airway inflammation is characteristic for the pathophysiology of chronic obstructive pulmonary disease (COPD). However, the key factors determining the decrease in lung function, an important clinical parameter of COPD, are not clear. Genome-wide linkage analyses provide evidence for significant linkage to airway obstruction susceptibility loci on chromosome 8p23, the location of the human defensin gene cluster. Moreover, a genetic variation in the defensin beta 1 (DEFB1) gene was found to be associated with COPD. Therefore, we hypothesized that DEFB1 is differently regulated and expressed in human lungs during COPD progression. Gene expression of DEFB1 was assessed in bronchial epithelium and BAL fluid cells of healthy controls and patients with COPD and using bisulfite sequencing and ChIP analysis, the epigenetic control of DEFB1 mRNA expression was investigated. We can demonstrate that DEFB1 mRNA expression was significantly increased in bronchopulmonary specimen of patients with COPD (n = 34) vs. healthy controls (n = 10) (p<0.0001). Furthermore, a significant correlation could be detected between DEFB1 and functional parameters such as FEV1 (p = 0.0024) and the FEV1/VC ratio (p = 0.0005). Upregulation of DEFB1 mRNA was paralleled by changes in HDAC1-3, HDAC5 and HDAC8 mRNA expression. Whereas bisulfite sequencing revealed no differences in the methylation state of DEFB1 promoter between patients with COPD and controls, ChIP analysis showed that enhanced DEFB1 mRNA expression was associated with the establishment of an active histone code. Thus, expression of human DEFB1 is upregulated and related to the decrease in pulmonary function in patients with COPD
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