161 research outputs found

    Living donor hand-assisted laparoscopic nephrectomy in a healthy individual with situs inversus totalis:no need to turn down the donor

    Get PDF
    A 70-year-old healthy male individual offered to undergo a living donor hand-assisted laparoscopic nephrectomy to enable kidney transplantation for a close relative. As required for all living transplant donor candidates, extensive screening was performed to exclude potential contraindications for donation. Tests revealed a situs inversus totalis, meaning a complete transposition of the thoracic and abdominal organs in the sagittal plane. As other contraindications for living kidney donation were absent, the feasibility of this procedure was determined multidisciplinary. A successful donation procedure was performed without surgical complications for the donor and good short-term transplant outcomes. In line with current developments that have resulted in more liberal criteria for potential living kidney donors, major anatomical deviations should not automatically be a contraindication. With multidisciplinary efforts and thorough surgical preparation at a high-volume transplant centre, this procedure is feasible and safe

    Centering, scaling, and transformations: improving the biological information content of metabolomics data

    Get PDF
    BACKGROUND: Extracting relevant biological information from large data sets is a major challenge in functional genomics research. Different aspects of the data hamper their biological interpretation. For instance, 5000-fold differences in concentration for different metabolites are present in a metabolomics data set, while these differences are not proportional to the biological relevance of these metabolites. However, data analysis methods are not able to make this distinction. Data pretreatment methods can correct for aspects that hinder the biological interpretation of metabolomics data sets by emphasizing the biological information in the data set and thus improving their biological interpretability. RESULTS: Different data pretreatment methods, i.e. centering, autoscaling, pareto scaling, range scaling, vast scaling, log transformation, and power transformation, were tested on a real-life metabolomics data set. They were found to greatly affect the outcome of the data analysis and thus the rank of the, from a biological point of view, most important metabolites. Furthermore, the stability of the rank, the influence of technical errors on data analysis, and the preference of data analysis methods for selecting highly abundant metabolites were affected by the data pretreatment method used prior to data analysis. CONCLUSION: Different pretreatment methods emphasize different aspects of the data and each pretreatment method has its own merits and drawbacks. The choice for a pretreatment method depends on the biological question to be answered, the properties of the data set and the data analysis method selected. For the explorative analysis of the validation data set used in this study, autoscaling and range scaling performed better than the other pretreatment methods. That is, range scaling and autoscaling were able to remove the dependence of the rank of the metabolites on the average concentration and the magnitude of the fold changes and showed biologically sensible results after PCA (principal component analysis). In conclusion, selecting a proper data pretreatment method is an essential step in the analysis of metabolomics data and greatly affects the metabolites that are identified to be the most important

    Variation of the redox conditions and the resultant phase assemblages during iron ore sintering

    Get PDF
    The oxygen potential prevailing during iron ore sintering wasmeasuredwith a zirconia sensor in a series of sinter pot experiments. Thiswas done to get a better indication of the redox conditions during commercial sintering. It was found that the pO2 is appreciably more oxidizing than previously assumed, with a minimum value of ~0.01 atm. It is concluded that this value represents the oxygen potential of the gas phase and it is therefore a mixture of combustion gas and downdraft air. The contents of a quenched sinter pot where the reactions were interrupted with the flame front situated midway through the sinter bed were investigated. X-ray diffraction analysis, using an internal standard to quantify the amorphous slag phase, revealed that at the flame front only magnetite and slag were present. SFCA phases only formed at the top of the bed after the flame front had passed. Thermodynamicmodeling of the phases at equilibriumagree qualitativelywith the phase analysis and explained the extensive presence of magnetite and melt, as well as the formation of calcium ferrite phases during cooling below 1100 °C.Kumba in the form of a bursary.http://www.elsevier.com/locate/ijminpro2017-05-31hb2016Materials Science and Metallurgical Engineerin

    Trends in Tissue Engineering for Blood Vessels

    Get PDF
    Over the years, cardiovascular diseases continue to increase and affect not only human health but also the economic stability worldwide. The advancement in tissue engineering is contributing a lot in dealing with this immediate need of alleviating human health. Blood vessel diseases are considered as major cardiovascular health problems. Although blood vessel transplantation is the most convenient treatment, it has been delimited due to scarcity of donors and the patient's conditions. However, tissue-engineered blood vessels are promising alternatives as mode of treatment for blood vessel defects. The purpose of this paper is to show the importance of the advancement on biofabrication technology for treatment of soft tissue defects particularly for vascular tissues. This will also provide an overview and update on the current status of tissue reconstruction especially from autologous stem cells, scaffolds, and scaffold-free cellular transplantable constructs. The discussion of this paper will be focused on the historical view of cardiovascular tissue engineering and stem cell biology. The representative studies featured in this paper are limited within the last decade in order to trace the trend and evolution of techniques for blood vessel tissue engineering

    Standardized, Modular Parallelization Platform for Microfluidic Large-Scale Integration Cell Culturing Chips

    Get PDF
    Standardized high-throughput devices for microfluidic cell cultures are necessary to translate discoveries made in academia to applications in pharmaceutical industry. Here we present a platform with integrated pneumatic valves for standardized parallelization of multichamber chips (SPARC). In total, 192 chambers divided over three microfluidic building blocks (MFBBs) can be filled and purged with spatial and temporal independence. The dimensions of both the MFBB and the platform are standardized and thus compatible with common lab equipment. We characterize the valves at different pumping and gate pressures and show that the MFBBs are suitable for culturing human umbilical vein endothelial cells (HUVECs)

    Trends in Tissue Engineering for Blood Vessels

    Get PDF
    Over the years, cardiovascular diseases continue to increase and affect not only human health but also the economic stability worldwide. The advancement in tissue engineering is contributing a lot in dealing with this immediate need of alleviating human health. Blood vessel diseases are considered as major cardiovascular health problems. Although blood vessel transplantation is the most convenient treatment, it has been delimited due to scarcity of donors and the patient’s conditions. However, tissue-engineered blood vessels are promising alternatives as mode of treatment for blood vessel defects. The purpose of this paper is to show the importance of the advancement on biofabrication technology for treatment of soft tissue defects particularly for vascular tissues. This will also provide an overview and update on the current status of tissue reconstruction especially from autologous stem cells, scaffolds, and scaffold-free cellular transplantable constructs. The discussion of this paper will be focused on the historical view of cardiovascular tissue engineering and stem cell biology. The representative studies featured in this paper are limited within the last decade in order to trace the trend and evolution of techniques for blood vessel tissue engineering

    Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

    Get PDF
    The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD

    Meta-analysis of Genome-Wide Association Studies for Extraversion : Findings from the Genetics of Personality Consortium

    Get PDF
    Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion.Peer reviewe
    corecore