909 research outputs found
Improvement of lung preservation - From experiment to clinical practice
Full text linkBackground. Reperfusion injury represents a severe early complication following lung transplantation. Among the pathogenetic factors, the high potassium content of Euro-Collins(R) solution is discussed. Material and Methods: In a pig model of orthotopic left-sided lung transplantation we investigated the effect of Euro-Collins solution (EC: n=6) versus low potassium dextran (LPD: Perfadex(R): n = 6). Sham-operated (n = 6) animals served as control. Transplant function, cellular energy metabolism and endothelial morphology served as parameters. In a clinical investigation, 124 patients were evaluated following single (EC: n = 31; LPD n = 37) or double (EC: n = 17; LPD n = 39) lung transplantation, whose organs where preserved with EC (n = 48) or LPD (n = 76). Duration of ischemia, duration of ventilation and stay on ICU were registered. Primary transplant function was evaluated according to AaDO(2) values. Cause of early death (30 days) was declared. Results: Experimental results: After flush with EC and 18 h ischemia, a reduction of tissue ATP content (p < 0.01 vs inital value and LPD) was noted. Endothelial damage after ischemia was severe (p < 0.05 vs control), paO(2) was significantly decreased. Clinical results: In the LPD group, duration of ischemia was longer for the grafts transplanted first (SLTx and DLTx: p = 0.0009) as well as second (2. organ DLTx: p = 0.045). Primary transplant function was improved (day 0: SLTx: p = 0.0015; DLTx: p = 0.0095, both vs EC). Duration of ventilation and stay on ICU were shorter (n.s.). Reperfusion injury-associated death was reduced from 8% (EC) to 0 (LPD). Conclusion: In experimental lung preservation, LPD lead to an improved graft function. These results were confirmed in clinical lung transplantation. Clinical lung preservation, therefore, should be carried out by use of LPD. Copyright (C) 2002 S. Karger AG, Basel
Current concepts on oxidative/carbonyl stress, inflammation and epigenetics in pathogenesis of chronic obstructive pulmonary disease
Full text linkChronic obstructive pulmonary disease (COPD) is a global health problem. The current therapies for COPD are poorly effective and the mainstays of pharmacotherapy are bronchodilators. A better understanding of the pathobiology of COPD is critical for the development of novel therapies. In the present review, we have discussed the roles of oxidative/aldehyde stress, inflammation/immunity, and chromatin remodeling in the pathogenesis of COPD. An imbalance of oxidants/antioxidants caused by cigarette smoke and other pollutants/biomass fuels plays an important role in the pathogenesis of COPD by regulating redox-sensitive transcription factors (e.g., NF-κB), autophagy and unfolded protein response leading to chronic lung inflammatory response. Cigarette smoke also activates canonical/alternative NF-κB pathways and their upstream kinases leading to sustained inflammatory response in lungs. Recently, epigenetic regulation has been shown to be critical for the development of COPD because the expression/activity of enzymes that regulate these epigenetic modifications have been reported to be abnormal in airways of COPD patients. Hence, the significant advances made in understanding the pathophysiology of COPD as described herein will identify novel therapeutic targets for intervention in COPD
Magnetic resonance imaging of pediatric lung parenchyma, airways, vasculature, ventilation, and perfusion: state of the art
No full textMagnetic resonance (MR) imaging is a noninvasive imaging modality, particularly attractive for pediatric patients given its lack of ionizing radiation. Despite many advantages, the physical properties of the lung (inherent low signal-to-noise ratio, magnetic susceptibility differences at lung-air interfaces, and respiratory and cardiac motion) have posed technical challenges that have limited the use of MR imaging in the evaluation of thoracic disease in the past. However, recent advances in MR imaging techniques have overcome many of these challenges. This article discusses these advances in MR imaging techniques and their potential role in the evaluation of thoracic disorders in pediatric patients
The five-item Brief-Symptom Rating Scale as a suicide ideation screening instrument for psychiatric inpatients and community residents
Full text linkAbstract Background An efficient screening instrument which can be used in diverse settings to predict suicide in different populations is vital. The aim of this study was to use the five-item Brief Symptom Rating Scale (BSRS-5) as a screening instrument for the prediction of suicide ideation in psychiatric, community and general medical settings. Methods Five hundred and one psychiatric, 1,040 community and 969 general medical participants were recruited. The community participants completed a structured telephone interview, and the other two groups completed the self-report BSRS-5 questionnaire. Results The logistic regression analysis showed that the predictors of suicide ideation for the psychiatric group were depression, hostility and inferiority (p p = 0.016, p = 0.011), for the community group, inferiority, hostility and insomnia (p p p = 0.003), and for the general medical group, inferiority, hostility, depression and insomnia (p p = 0.001, p = 0.020, p = 0.008). The structural equation model showed the same symptom domains that predicted suicide ideation for all three groups. The receiver operating characteristic curve using the significant symptom domains from logistic regression showed that for the psychiatric group, the optimal cut-off point was 4/5 for the total of the significant dimensions (positive predictive value [PPV] = 78.01%, negative predictive value [NPV] = 79.05%), for the community group, 7/8 (PPV = 68.75%, NPV = 96.09%), and for the general medical group, 12/13 (PPV = 92.86%, NPV = 88.48%). Conclusion The BSRS-5 is an efficient tool for the screening of suicide ideation-prone psychiatric inpatients, general medical patients, and community residents. Understanding the discriminative symptom domains for different groups and the relationship between them can help health care professionals in their preventative programs and clinical treatment.</p
Transcriptional Blood Signatures Distinguish Pulmonary Tuberculosis, Pulmonary Sarcoidosis, Pneumonias and Lung Cancers
Full text linkRationale
New approaches to define factors underlying the immunopathogenesis of pulmonary diseases including sarcoidosis and tuberculosis are needed to develop new treatments and biomarkers. Comparing the blood transcriptional response of tuberculosis to other similar pulmonary diseases will advance knowledge of disease pathways and help distinguish diseases with similar clinical presentations.
Objectives
To determine the factors underlying the immunopathogenesis of the granulomatous diseases, sarcoidosis and tuberculosis, by comparing the blood transcriptional responses in these and other pulmonary diseases.
Methods
We compared whole blood genome-wide transcriptional profiles in pulmonary sarcoidosis, pulmonary tuberculosis, to community acquired pneumonia and primary lung cancer and healthy controls, before and after treatment, and in purified leucocyte populations.
Measurements and Main Results
An Interferon-inducible neutrophil-driven blood transcriptional signature was present in both sarcoidosis and tuberculosis, with a higher abundance and expression in tuberculosis. Heterogeneity of the sarcoidosis signature correlated significantly with disease activity. Transcriptional profiles in pneumonia and lung cancer revealed an over-abundance of inflammatory transcripts. After successful treatment the transcriptional activity in tuberculosis and pneumonia patients was significantly reduced. However the glucocorticoid-responsive sarcoidosis patients showed a significant increase in transcriptional activity. 144-blood transcripts were able to distinguish tuberculosis from other lung diseases and controls.
Conclusions
Tuberculosis and sarcoidosis revealed similar blood transcriptional profiles, dominated by interferon-inducible transcripts, while pneumonia and lung cancer showed distinct signatures, dominated by inflammatory genes. There were also significant differences between tuberculosis and sarcoidosis in the degree of their transcriptional activity, the heterogeneity of their profiles and their transcriptional response to treatment
Influence of lung function on course of disease and response to antibiotic therapy in adult primary care patients with acute cough: a post hoc analysis of patients enrolled in a prospective multicentre study
No full textBACKGROUND: In acute cough patients, impaired lung function as present in chronic lung conditions like asthma and chronic obstructive pulmonary disease (COPD) are often thought to negatively influence course of disease, but clear evidence is lacking.AIMS: To investigate the influence of lung function abnormalities on course of disease and response to antibiotic therapy in primary care patients with acute cough.METHODS: A total of 3,104 patients with acute cough (?28 days) were included in a prospective observational study with a within-nested trial, of which 2,427 underwent spirometry 28-35 days after inclusion. Influence of the lung function abnormalities fixed obstruction (forced expiratory volume in 1?s (FEV1)/forced vital capacity (FVC) ratio <0.7) and bronchodilator responsiveness (FEV1 increase of ?12% or 200?ml after 400??g salbutamol) on symptom severity, duration and worsening were evaluated using uni- and multivariable regression models. Antibiotic use was defined as the reported use of antibiotics ?5 days in the first week. Interaction terms were calculated to investigate modifying effects of lung function on antibiotic effect.RESULTS: The only significant association was the effect of severe airway obstruction on symptom severity on days 2-4 (difference=0.31, 95% confidence interval (CI)=0.03-0.60, P=0.03). No evidence of a differential effect of lung function on the effect of antibiotics was found. Prior use of inhaled steroids was associated with a 30% slower resolution of symptoms rated 'moderately bad' or worse (hazard ratio=0.75, 95% CI=0.63-0.90, P=0.00).CONCLUSIONS: In adult patients with acute cough, lung function abnormalities were neither significantly associated with course of disease nor did they modify the effect of antibiotics
Damage mechanism characterization of ±35° and ±55° FW composite tubes using acoustic emission method
No full textThe focus of this study is to investigate the mechanical properties, of ±35° and ±55° filament wound (FW) composite tubes under axial compression loading using the acoustic emission technique. For this purpose, material failure, crashworthiness characteristics, and the effect of each mechanism on the energy absorption capacity were studied using numerical and experimental approaches. Also, to identify and estimate the contribution percentage of damage mechanisms as well as how the damage grows in the specimens, the analysis of acoustic emission signals recorded during loading was performed. Digital image correlation was additionally used to capture displacement/strain contour maps. Finally, to analyze the effect of the winding pattern in the experimental test, the tubes were simulated using finite element analysis (FEA). For modeling of damage mechanisms, a 3D continuum damage model was used. The results of signal processing showed that by increasing the weaving angle of fibers from ±35° to ±55°, the separation of fibers from the matrix decreases, and the percentage of matrix crushing and fiber failure increases. The assessment of damage percentages showed that the reason for the large drop in force at ±55° compared to ±35° is the increase in matrix crushing. Furthermore, the failure behavior of FW tubes appeared to be dominated by local buckling, and the FEA effectively predicted the linear behavior and maximum load value of the composite tubes.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Ship Hydromechanics and Structure
Lung function in the general population : the complex interplay of variants in "Serpina1" and other genes with the environment
Full text linkBackground. One of the globally most frequent health problems are obstructive lung
diseases such as asthma and chronic obstructive pulmonary disease. Both of them
show heterogeneous phenotypes and are most commonly diagnosed by lung function
measurements. Apart from several well-established environmental risk factors,
there are also genetic factors which play an important role in determining lung
function. Notably, SERPINA1 gene variants which severely reduce the
alpha1-antitrypsin (AAT) concentration in the blood and consequently lead to a
protease-antiprotease disequilibrium in the lung have been known as risk factors
for several years. Intermediate deficiency of AAT serum level is however assumed
to be a risk factor in only part of the population, but neither is it entirely
clear how to define this range of protein concentration for the general population,
nor do we know which co-factors are health-relevant in intermediately deficient individuals.
Methods. In this work, SAPALDIA, the Swiss cohort study on air pollution and lung disease
in adults, was used to find the essential genetic polymorphisms which determine AAT serum
level. Deficiency ranges for AAT were defined in the general population, and the association
between SERPINA1 deficiency genotypes and age-related lung function decline was investigated
in a comprehensive way. The assessment of gene-environment interactions in terms of pulmonary
health was a central part of this work and embraced also genes beyond SERPINA1. The
environment-related focus was set on factors associated with inflammatory stress, namely smoking,
air pollution, high occupational exposure to vapours, gas, dusts and fumes as well as obesity.
The availability of serum inflammatory markers including AAT, genome-wide data including
additional genotype and sequence information of the SERPINA1 gene as well as very comprehensive
and detailed environmental and respiratory health data made SAPALDIA, unlike any other study,
ideally suited to investigate the aforementioned associations and interactions.
Results. This work found a smaller range of AAT serum level in subjects with intermediate AAT
deficiency than reported in the literature and clarified the role of elevated inflammatory
conditions on AAT serum level. It confirmed uncommon variants in the SERPINA1 locus as the
major genetic determinants of AAT blood level and pointed to some of the inherent weaknesses
of genome-wide association studies. A high burden of inflammatory stress was suggested to
modify the association between intermediate AAT deficiency and lung function decline. Further
genetic interaction with obesity in terms of asthma and with air pollution in terms of lung
function decline was suggested, pointing on the one hand to a still proliferative research
area of gene-environment interactions which has not yet been systematically assessed, but
revealing on the other hand the complexity of drawing firm conclusions from such analyses.
Discussion and Conclusion. In summary, this work may potentially facilitate the diagnostic
procedure for subjects with an assumed AAT deficiency. Although generally not regarded
as a risk group for adverse pulmonary health, individuals with an intermediate AAT
deficiency seem more susceptible to elevated inflammatory conditions compared to the
general population. They would potentially more strongly benefit from measures like
counselling against the uptake of smoking, for healthy diet programmes or improvements
of occupational safety
Photometric study of two detached binaries FW Vel and BB Mon
Full text link32nd International Physics Congress of Turkish-Physical-Society (TPS) -- SEP 06-09, 2016 -- Bodrum, TURKEYWe present the first analysis of photometric observations of two detached binary stars, FW Vel and BB Mon. Their V light curves from the All Sky Automated Survey were solved using Monte Carlo Search Method. The final solutions describe these two systems as Algol-like binary stars with detached configurations. The absolute parameters of the components of the systems were also estimated.Turkish Phys So
Aircraft hydraulic power system diagnostic, prognostics and health management
Full text linkThis Individual Research Project (IRP) is the extension research to the group design project (GDP) work which the author has participated in his Msc programme. The GDP objective is to complete the conceptual design of a 200-seat, flying wing civil airliner—FW-11. The next generation aircraft design demands higher reliability, safety and maintainability.
With the development of the vehicle hydraulic system technology, the equipment and systems become more and more complex, their reliability and maintenance become more difficult for designers, manufacturers and customers. To improve the mission reliability and reduce life cycle cost, there is strong demand for the application of health management technology into airframe system design.
In this research, the author introduced diagnostic, prognostic and health management (DPHM) concept into the aircraft hydraulic power system development. As a brand new technology, it is a challenge to apply the DPHM techniques to on-board system. Firstly, an assumed hydraulic power system was designed for FW-11 by the author and used as the case in his IRP research. Then the crucial components and key parameters needed to be monitored were obtained based on Function Hazard Analysis and Failure Modes Effects Analysis of this system. The writer compared a few diagnostic and prognostic methods in detail, and then selected suitable ones for a hydraulic power system. A diagnostic process was applied to the hydraulic power system using a Case-based reasoning (CBR) approach, whilst a hybrid prognostic method was suggested for the system. After that, a diagnostic, prognostic and health management (DPHM) architecture of the hydraulic power system was designed at system level based on the diagnostic and prognostic research. The whole research work provided a general and practical instruction for hydraulic system design by means of DPHM application
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