1,232 research outputs found
The in ovo CAM-assay as a xenograft model for sarcoma
Sarcoma is a very rare disease that is heterogeneous in nature, all hampering the development of new therapies. Sarcoma patients are ideal candidates for personalized medicine after stratification, explaining the current interest in developing a reproducible and low-cost xenotransplant model for this disease. The chick chorioallantoic membrane is a natural immunodeficient host capable of sustaining grafted tissues and cells without species-specific restrictions. In addition, it is easily accessed, manipulated and imaged using optical and fluorescence stereomicroscopy. Histology further allows detailed analysis of heterotypic cellular interactions.
This protocol describes in detail the in ovo grafting of the chorioallantoic membrane with fresh sarcoma-derived tumor tissues, their single cell suspensions, and permanent and transient fluorescently labeled established sarcoma cell lines (Saos-2 and SW1353). The chick survival rates are up to 75%. The model is used to study graft-(viability, Ki67 proliferation index, necrosis, infiltration) and host (fibroblast infiltration, vascular ingrowth) behavior. For localized grafting of single cell suspensions, ECM gel provides significant advantages over inert containment materials. The Ki67 proliferation index is related to the distance of the cells from the surface of the CAM and the duration of application on the CAM, the latter determining a time frame for the addition of therapeutic products
Discovery of (S)-3′-hydroxyblebbistatin and (S)-3′-aminoblebbistatin : polar myosin II inhibitors with superior research tool properties
In search of myosin II inhibitors with superior research tool properties, a chemical optimization campaign of the blebbistatin scaffold was conducted in this paper. (S)-Blebbistatin is the best known small-molecule inhibitor of myosin II ATPase activity. Unfortunately, as a research tool this compound has several deficiencies: it is photolabile and (photo) toxic, has low water solubility, and its (fluorescent) precipitates interfere in (fluorescence) readouts. In view of obtaining tool compounds with improved properties, both enantiomers of a series of D-ring modified polar analogs were prepared. We identified (S)-3'-hydroxyblebbistatin (S)-2 and (S)-3'-aminoblebbistatin (S)-3 as two myosin II inhibitors with a 30-fold higher water solubility than (S)-blebbistatin. These molecules furthermore do not cause interference in (fluorescence) readouts. (S)-2 and (S)-3 thus are superior alternatives to (S)-blebbistatin as research tools to study myosin II
Ventricular septal defect due to blunt chest trauma
Blunt chest trauma may cause cardiac trauma, this possibility often being overlooked. Various anatomical structures may be affected. A case of ventr'icular septal defect due to blunt chest trauma is described and the relevant literature is reviewed
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Fast and slow shifts of the zonal-mean intertropical convergence zone in response to an idealized anthropogenic aerosol
Previous modeling work showed that aerosol can affect the position of the tropical rain belt, i.e., the intertropical convergence zone (ITCZ). Yet it remains unclear which aspects of the aerosol impact are robust across models, and which are not. Here we present simulations with seven comprehensive atmosphere models that study the fast and slow impacts of an idealized anthropogenic aerosol on the zonal-mean ITCZ position. The fast impact, which results from aerosol atmospheric heating and land cooling before sea-surface temperature (SST) has time to respond, causes a northward ITCZ shift. Yet the fast impact is compensated locally by decreased evaporation over the ocean, and a clear northward shift is only found for an unrealistically large aerosol forcing. The local compensation implies that while models differ in atmospheric aerosol heating, this does not contribute to model differences in the ITCZ shift. The slow impact includes the aerosol impact on the ocean surface energy balance and is mediated by SST changes. The slow impact is an order of magnitude more effective than the fast impact and causes a clear southward ITCZ shift for realistic aerosol forcing. Models agree well on the slow ITCZ shift when perturbed with the same SST pattern. However, an energetic analysis suggests that the slow ITCZ shifts would be substantially more model-dependent in interactive-SST setups due to model differences in clear-sky radiative transfer and clouds. We also discuss implications for the representation of aerosol in climate models and attributions of recent observed ITCZ shifts to aerosol
Exploring patient satisfaction after operative and nonoperative treatment for midshaft clavicle fractures:a focus group analysis
Background: There is no consensus on the optimal treatment for displaced midshaft clavicle fractures. Several studies indicate superior patient satisfaction in favour of operative reconstruction. It is unknown what drives superior satisfaction in this treatment group. The aim of this study was to explore patient satisfaction and identify contributors to patient satisfaction after operative and nonoperative treatment for displaced midshaft clavicle fractures in adults using a focus group approach. Methods: Four face-to-face and two web-based focus groups were hosted. A total of 24 participants who were treated nonoperatively (n = 14) or operatively (n = 10) agreed to participate. Participants were selected using purposive sampling, ensuring variation in gender, age, treatment complications and outcomes. A question script was developed to systematically explore patient expectations, attitudes and satisfaction with different dimensions of care. All focus groups were voice-recorded and transcribed at verbatim. Thematic analysis was conducted on all face-to-face and web-based transcripts. Results: The main emerging themes across treatment groups were; need for more information, functional recovery, speed of recovery and patient-doctor interaction. There was no difference in themes observed between operative and nonoperative focus groups. The lack of information was the most important complaint in dissatisfied patients. Conclusion: Our study shows that informing patients about their injury, treatment options and expectations for recovery is paramount for overall patient satisfaction after treatment for a displaced midshaft clavicle fracture. Level of evidence: Level III, focus group study. </p
Fractionation of Adipose Tissue Procedure With a Disposable One-Hole Fractionator
Background: Adipose tissue has been widely used in regenerative surgery for its therapeutic potential. This potential is often ascribed to the stromal vascular fraction (SVF), which can be mechanically isolated. Mechanical isolation results in an SVF that retains intact cell-cell communication including extracellular matrix and is therefore named tissue-SVF (tSVF). Objectives: The aim of this study was to evaluate a new disposable 1-hole fractionator for fractionation of adipose tissue (FAT), and compare this new device with the existing reusable 3-hole fractionator. Methods: The composition of tSVF obtained via the 1-hole fractionator was histologically and histochemically compared to unprocessed adipose tissue. The number of viable nuclear cells in tSVF obtained by the 1-hole and 3-hole fractionators as well as unprocessed adipose tissue were compared after enzymatic isolation and tested for colony-forming capacity. Flow cytometry was used to compare different cell compositions based on surface marker expression between tSVF isolated by the two types of fractionators. Results: Fractionation of adipose tissue with the 1-hole fractionator condenses vasculature and extracellular matrix by disrupting adipocytes. The number of viable nuclear cells in tSVF obtained with the two fractionators was comparable and significantly higher than unprocessed lipoaspirate. Furthermore, tSVF isolated by both fractionators showed similar cell compositions and comparable colony-forming capacities. Conclusions: FAT with a disposable 1-hole fractionator effectively isolates tSVF with a cell count and cell composition comparable to the fraction obtained with the 3-hole reusable fractionator. The disposable 1-hole fractionator, however, is safer and more user friendly
Mapping data elements to terminological resources for integrating biomedical data sources
BACKGROUND: Data integration is a crucial task in the biomedical domain and integrating data sources is one approach to integrating data. Data elements (DEs) in particular play an important role in data integration. We combine schema- and instance-based approaches to mapping DEs to terminological resources in order to facilitate data sources integration. METHODS: We extracted DEs from eleven disparate biomedical sources. We compared these DEs to concepts and/or terms in biomedical controlled vocabularies and to reference DEs. We also exploited DE values to disambiguate underspecified DEs and to identify additional mappings. RESULTS: 82.5% of the 474 DEs studied are mapped to entries of a terminological resource and 74.7% of the whole set can be associated with reference DEs. Only 6.6% of the DEs had values that could be semantically typed. CONCLUSION: Our study suggests that the integration of biomedical sources can be achieved automatically with limited precision and largely facilitated by mapping DEs to terminological resources
Focus EMU, February 22, 2005
Une opinion rédigée et transmise à la Première ministre et aux Ministresprésidents
régionaux par un collectif de signataires
Durability improvement of wood by treatment with Methyl Alkenoate Succinic Anhydrides (M-ASA) of vegetable origin
Methyl Alkenoate Succinic Anhydride (M-ASA) is the product of the reaction between methyl esters of fatty acids and maleic anhydride. Crude M-ASA was synthesized from rapeseed oil methyl esters. The main compounds in this adduct are methyl oleate succinic anhydride (30%), methyl linoleate succinic anhydride (24%), unreacted methyl esters (41%) and unreacted maleic anhydride (4%). The treatment of wood at high temperature with crude M-ASA conferred protection against fungal decay and insects. Biological tests were carried out on Scots pine (Pinus sylvestris) sapwood and beech (Fagus sylvatica) according to European standards. M-ASA treatment was efficient against mould fungi (BS 3900), blue staining (EN 152), white and brown rot fungi (EN 113), longhorn beetle larvae (EN 46 and 47) and termites (EN 117). This treatment delayed the degradation of wood by soft rot (ENV 807) but it did not prevent it. Therefore, M-ASA combines all the necessary conditions to fulfil the requirements of the biological use classes 2 and 3, but not for class 4
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