67 research outputs found
Instructing human macrophage polarization by stiffness and glycosaminoglycan functionalization in 3D collagen networks
Dynamic alterations of composition and mechanics of the extracellular matrix (ECM) are suggested to modulate cellular behavior including plasticity of macrophages (MPhs) during wound healing. In this study, engineered 3D fibrillar matrices based on naturally occurring biopolymers (collagen I, glycosaminoglycans (GAGs)) were used to mimic matrix stiffening as well as modification by sulfated and non-sulfated GAGs at different stages of wound healing. Human MPhs were found to sensitively respond to these microenvironmental cues in terms of polarization towards pro-inflammatory or wound healing phenotypes over 6 days in vitro. MPhs exhibited a wound healing phenotype in stiffer matrices as determined by protein and gene expression of relevant cytokines (IL10, IL12, TNF). Presence of sulfated and non-sulfated GAGs inhibited this polarization effect. Furthermore, control experiments on 2D matrices stressed the relevance of using stiffness-controlled 3D matrices, as MPhs showed a reciprocal polarization behavior depending on GAG presence. Hence, the results indicate a strong influence of dimensionality, stiffness, and GAG presence of the biomaterial scaffold on MPh polarization and emphasize the need for matrices closely mimicking the 3D in vivo context with a variable stiffness and GAG composition in in vitro studies
Does subarachnoid haemorrhage affect the innate immune response?
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Inter-observer and inter-examination variability of manual vertebral bone attenuation measurements on computed tomography
Objective: To determine inter-observer and inter-examination variability of manual attenuation measurements of the vertebrae in low-dose unenhanced chest computed tomography (CT).
Methods: Three hundred and sixty-seven lung cancer screening trial participants who underwent baseline and repeat unenhanced low-dose CT after 3 months because of an indeterminate lung nodule were included. The CT attenuation value of the first lumbar vertebrae (L1) was measured in all CTs by one observer to obtain inter-examination reliability. Six observers performed measurements in 100 randomly selected CTs to determine agreement with limits of agreement and Bland-Altman plots and reliability with intraclass correlation coefficients (ICCs). Reclassification analyses were performed using a threshold of 110 HU to define osteoporosis.
Results: Inter-examination reliability was excellent with an ICC of 0.92 (p < 0.001). Inter-examination limits of agreement ranged from -26 to 28 HU with a mean difference of 1 ± 14 HU. Inter-observer reliability ICCs ranged from 0.70 to 0.91. Inter-examination variability led to 11.2 % reclassification of participants and inter-observer variability led to 22.1 % reclassification.
Conclusions: Vertebral attenuation values can be manually quantified with good to excellent inter-examination and inter-observer reliability on unenhanced low-dose chest CT. This information is valuable for early detection of osteoporosis on low-dose chest CT. Key Points: • Vertebral attenuation values can be manually quantified on low-dose unenhanced CT reliably.• Vertebral attenuation measurements may be helpful in detecting subclinical low bone density.• This could become of importance in the detection of osteoporosis
Cancer survival in the elderly: Effects of socio-economic factors and health care system features (ELDCARE project)
The purpose of the ELDCARE project is to study differences in cancer survival for elderly patients by country, taking into account the socio-economic conditions and the characteristics of health care systems at the ecological level. Fifty-three European cancer registries, from 19 countries, participating in the EUROCARE 3 programme, collected information to compute relative survival on patients aged 65-84 years, diagnosed over the period 1990-1994. National statistics offices provided the macro-economic and labour force indicators (gross domestic product, total health expenditure, and proportion of people employed in the agriculture sector) as well as the features of national health care systems. Survival for several of the cancer sites had high positive Pearson's correlations (r) with the affluence indicators (usually r > 0.7), but survival for the poor prognosis cancers (lung, ovary, stomach) and for cervix uteri was not so well correlated. Among the medical resources considered, the number of computed tomography scanners was the variable most related to survival in the elderly; the number of total health practitioners in the country did not show any relationship. Survival was related to the marital status of elderly women more strongly than for men and younger people. The highest correlations of survival with the percentage of married elderly women in the population were for cancers of the rectum (r = 0.79) and breast (r = 0.66), while survival correlated negatively with the proportion of widows for most cancers. Being married or widowed is for elderly people, in particular elderly women, an important factor influencing psychological status, life habits and social relationships. Social conditions could play a major role in determining health outcomes, particularly in the elderly, by affecting access to health care and delay in diagnosis
CT-Based Local Distribution Metric Improves Characterization of COPD
Parametric response mapping (PRM) of paired CT lung images has been shown to improve the phenotyping of COPD by allowing for the visualization and quantification of non-emphysematous air trapping component, referred to as functional small airways disease (fSAD). Although promising, large variability in the standard method for analyzing PRM(fSAD) has been observed. We postulate that representing the 3D PRM(fSAD) data as a single scalar quantity (relative volume of PRM(fSAD)) oversimplifies the original 3D data, limiting its potential to detect the subtle progression of COPD as well as varying subtypes. In this study, we propose a new approach to analyze PRM. Based on topological techniques, we generate 3D maps of local topological features from 3D PRM(fSAD) classification maps. We found that the surface area of fSAD (S(fSAD)) was the most robust and significant independent indicator of clinically meaningful measures of COPD. We also confirmed by micro-CT of human lung specimens that structural differences are associated with unique S(fSAD) patterns, and demonstrated longitudinal feature alterations occurred with worsening pulmonary function independent of an increase in disease extent. These findings suggest that our technique captures additional COPD characteristics, which may provide important opportunities for improved diagnosis of COPD patients
Lower incidence rates but thicker melanomas in Eastern Europe before 1992: A comparison with Western Europe
The objective of this study was to investigate the epidemiology of melanoma across Europe with regard to Breslow thickness and body-site distribution. Incidence data from Cancer Incidence in 5 Continents and the EUROCARE-melanoma database were used: 28 117 melanoma cases from 20 cancer registries in 12 European countries, diagnosed between 1978 and 1992. Regression analysis and general linear modelling were used to analyse the data. Melanomas in Eastern Europe were on average 1.4 mm thicker (P<0.05) than in Western Europe and appeared more often on the trunk. From 1978 to 1992, their Breslow thickness had decreased in Western but not Eastern Europe. There was a latitude gradient in incidence, with highest rates in southern regions in Eastern Europe and an inverse gradient in Western Europe, with highest rates in the North. Mortality:incidence ratios were less favourable in southern parts across Europe, especially in Eastern Europe. If Eastern European populations copy the sunbathing behaviour of the West it is likely that in the near future a higher melanoma incidence can be expected there
Bankruptcy prediction: the influence of the year prior to failure selected for model building and the effects in a period of economic decline
Using large amounts of data from small and medium-sized industrial firms, this study examines two aspects of bankruptcy prediction: the influence of the year prior to failure selected for model building and the effects in a period of economic decline. The results show that especially models generated from the final annual report published prior to bankruptcy were less successful in the timely prediction of failure. Furthermore, it was found that economic decline coincided with the deterioration of a model's performance. With respect to the methods used, we found that neural networks had a somewhat better overall performance than multiple discriminant analysis
The prediction of bankruptcy of small- and medium-sized industrial firms
Using large amounts of data from small- and medium-sized industrial firms, this study examines several aspects of bankruptcy prediction. We have tested a hypothesis on the predictive power of different ratio categories during the successive phases before bankruptcy, and one on the relationship between the age of a firm and the predictability of bankruptcy. It was found that virtually every ratio investigated had some predictive power, and that the univariate and multivariate importance of ratio stability were not very high.\u
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