15 research outputs found
Hemodynamic Effects of Entry and Exit Tear Size in Aortic Dissection Evaluated with In Vitro Magnetic Resonance Imaging and Fluid-Structure Interaction Simulation
Understanding the complex interplay between morphologic and hemodynamic
features in aortic dissection is critical for risk stratification and for the
development of individualized therapy. This work evaluates the effects of entry
and exit tear size on the hemodynamics in type B aortic dissection by comparing
fluid-structure interaction (FSI) simulations with in vitro 4D-flow magnetic
resonance imaging (MRI). A baseline patient-specific 3D-printed model and two
variants with modified tear size (smaller entry tear, smaller exit tear) were
embedded into a flow- and pressure-controlled setup to perform MRI as well as
12-point catheter-based pressure measurements. The same models defined the wall
and fluid domains for FSI simulations, for which boundary conditions were
matched with measured data. Results showed exceptionally well matched complex
flow patterns between 4D-flow MRI and FSI simulations. Compared to the baseline
model, false lumen flow volume decreased with either a smaller entry tear
(-17.8 and -18.5 %, for FSI simulation and 4D-flow MRI, respectively) or
smaller exit tear (-16.0 and -17.3 %). True to false lumen pressure difference
(initially 11.0 and 7.9 mmHg, for FSI simulation and catheter-based pressure
measurements, respectively) increased with a smaller entry tear (28.9 and 14.6
mmHg), and became negative with a smaller exit tear (-20.6 and -13.2 mmHg).
This work establishes quantitative and qualitative effects of entry or exit
tear size on hemodynamics in aortic dissection, with particularly notable
impact observed on FL pressurization. FSI simulations demonstrate acceptable
qualitative and quantitative agreement with flow imaging, supporting its
deployment in clinical studies.Comment: Judith Zimmermann and Kathrin B\"aumler contributed equall
The Interaction of Canine Plasminogen with Streptococcus pyogenes Enolase: They Bind to One Another but What Is the Nature of the Structures Involved?
For years it has been clear that plasminogen from different sources and enolase from different sources interact strongly. What is less clear is the nature of the structures required for them to interact. This work examines the interaction between canine plasminogen (dPgn) and Streptococcus pyogenes enolase (Str enolase) using analytical ultracentrifugation (AUC), surface plasmon resonance (SPR), fluorescence polarization, dynamic light scattering (DLS), isothermal titration calorimetry (ITC), and simple pull-down reactions. Overall, our data indicate that a non-native structure of the octameric Str enolase (monomers or multimers) is an important determinant of its surface-mediated interaction with host plasminogen. Interestingly, a non-native structure of plasminogen is capable of interacting with native enolase. As far as we can tell, the native structures resist forming stable mixed complexes
Risk in Recovery: Views of Non-Executive Directors of UK Building Societies
This research report originated from general discussions regarding the difficult and
challenging role of Non-Executive Directors within and following on from the recent
financial crisis. Parallel discussions centred on the various mutual sectors and the
challenges, and opportunities that various mutual organisations might face as a ‘new
dawn’ begins to arise within the financial services industry. Building Societies represent
a very significant and long-standing mutual ‘force’, and the irony of seeing at the
centre of the UK’s financial woes the demise of former Building Societies all made for a
further research interest
Risk in Recovery: Views of Non Executive Directors of UK Building Societies
Financial crisis: worldwide, wide ranging impact on the wider financial service sector in the UK
Irony of demutualised institutions being at forefront none of the demutualised building societies exist as independent bodies
High profile collapse of former building societies, now banks, such as Northern Rock and the Halifax Bank of Scotland (HBOS
Mutations in CSTA, Encoding Cystatin A, Underlie Exfoliative Ichthyosis and Reveal a Role for This Protease Inhibitor in Cell-Cell Adhesion
Autosomal-recessive exfoliative ichthyosis presents shortly after birth as dry, scaly skin over most of the body with coarse peeling of nonerythematous skin on the palms and soles, which is exacerbated by excessive moisture and minor trauma. Using whole-genome homozygosity mapping, candidate-gene analysis and deep sequencing, we have identified loss-of-function mutations in the gene for protease inhibitor cystatin A (CSTA) as the underlying genetic cause of exfoliative ichthyosis. We found two homozygous mutations, a splice-site and a nonsense mutation, in two consanguineous families of Bedouin and Turkish origin. Electron microscopy of skin biopsies from affected individuals revealed that the level of detachment occurs in the basal and lower suprabasal layers. In addition, in vitro modeling suggests that in the absence of cystatin A protein, there is a cell-cell adhesion defect in human keratinocytes that is particularly prominent when cells are subject to mechanical stress. We show here evidence of a key role for a protease inhibitor in epidermal adhesion within the lower layers of the human epidermis
Psoriasis risk genes of the late cornified envelope-3 group are distinctly expressed compared with genes of other LCE groups
Item does not contain fulltextDeletion of the late cornified envelope (LCE) genes LCE3B and LCE3C has recently been identified as a risk factor for psoriasis. Expression of 16 LCE genes of LCE groups 1, 2, 3, 5, and 6 was examined in vivo and in vitro. Quantitative PCR demonstrated that moderate to high LCE expression was largely confined to skin and a few oropharyngeal tissues. Genes of the LCE3 group demonstrated increased expression in lesional psoriatic epidermis and were induced after superficial injury of normal skin, whereas expression of members of other LCE groups was down-regulated under these conditions. Immunohistochemistry and immunoelectron microscopy demonstrated that LCE2 protein expression was restricted to the uppermost granular layer and the stratum corneum. Stimulation of in vitro reconstructed skin by several psoriasis-associated cytokines resulted in induction of LCE3 members. The data suggest that LCE proteins of groups 1, 2, 5, and 6 are involved in normal skin barrier function, whereas LCE3 genes encode proteins involved in barrier repair after injury or inflammation. These findings may provide clues to the mechanistic role of LCE3B/C deletion in psoriasis
Food and environmental parasitology in Canada:A network for the facilitation of collaborative research
Parasitic diseases are of considerable public health significance in Canada, particularly in rural and remote areas. Food- and water-borne parasites contribute significantly to the overall number of parasitic infections reported in Canada. While data on the incidence of some of these diseases are available, knowledge of the true burden of infection by the causative agents in Canadians is somewhat limited. A number of centers of expertise in Canada study various aspects of parasitology, but few formal societies or networks of parasitologists currently exist in Canada, and previously none focused specifically on food or environmental transmission. The recently established Food and Environmental Parasitology Network (FEPN) brings together Canadian researchers, regulators and public health officials with an active involvement in issues related to these increasingly important fields. The major objectives of the Network include identifying research gaps, facilitating discussion and collaborative research, developing standardized methods, generating data for risk assessments, policies, and guidelines, and providing expert advice and testing in support of outbreak investigations and surveillance studies. Issues considered by the FEPN include contaminated foods and infected food animals, potable and non-potable water, Northern and Aboriginal issues, zoonotic transmission, and epidemiology