24 research outputs found
Bilateral accessory middle cerebral arteries associated with an aneurysm of the anterior circulation
An accessory middle cerebral artery is one variation of the intracranial vasculature
that may be a source of misinterpretation by clinicians dealing with cerebrovascular
diseases. We report a case of an elderly female found to have bilateral
accessory middle cerebral arteries, who presented with the rupture of an
aneurysm of the anterior part of the circle of Willis. Accessory middle cerebral
arteries are rare anatomical findings and the bilateral occurrence is exceedingly
rare. We believe this to be the first report of bilateral accessory middle cerebral
arteries associated with an aneurysm of the anterior cerebral-anterior communicating
arteries. The anatomical and clinical relevance of this variation is described
Quantifying distortions in two-photon remote focussing microscope images using a volumetric calibration specimen
This Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permission.Remote focussing microscopy allows sharp, in-focus images to be acquired at high speed from outside of the focal plane of an objective lens without any agitation of the specimen. However, without careful optical alignment, the advantages of remote focussing microscopy could be compromised by the introduction of depth-dependent scaling artifacts. To achieve an ideal alignment in a point-scanning remote focussing microscope, the lateral (XY) scan mirror pair must be imaged onto the back focal plane of both the reference and imaging objectives, in a telecentric arrangement. However, for many commercial objective lenses, it can be difficult to accurately locate the position of the back focal plane. This paper investigates the impact of this limitation on the fidelity of three-dimensional data sets of living cardiac tissue, specifically the introduction of distortions. These distortions limit the accuracy of sarcomere measurements taken directly from raw volumetric data. The origin of the distortion is first identified through simulation of a remote focussing microscope. Using a novel three-dimensional calibration specimen it was then possible to quantify experimentally the size of the distortion as a function of objective misalignment. Finally, by first approximating and then compensating the distortion in imaging data from whole heart rodent studies, the variance of sarcomere length (SL) measurements was reduced by almost 50%.Medical Research Council (MRC)Engineering and Physical Sciences Research Council (EPSRC)Biotechnology and Biological Sciences Research Council (BBSRC)British Heart Foundation Centre of Research Excellence, Oxfor
Adjusting for treatment switching in oncology trials: A systematic review and recommendations for reporting
Objectives
To systematically review the quality of reporting on the application of switching adjustment approaches in published oncology trials and industry submissions to the National Institute for Health and Care Excellence Although methods such as the rank preserving structural failure time model (RPSFTM) and inverse probability of censoring weights (IPCW) have been developed to address treatment switching, the approaches are not widely accepted within health technology assessment. This limited acceptance may partly be a consequence of poor reporting on their application.
Methods
Published trials and industry submissions were obtained from searches of PubMed and nice.org.uk, respectively. The quality of reporting in these studies was judged against a checklist of reporting recommendations, which was developed by the authors based on detailed considerations of the methods.
Results
Thirteen published trials and 8 submissions to nice.org.uk satisfied inclusion criteria. The quality of reporting around the implementation of the RPSFTM and IPCW methods was generally poor. Few studies stated whether the adjustment approach was prespecified, more than a third failed to provide any justification for the chosen method, and nearly half neglected to perform sensitivity analyses. Further, it was often unclear how the RPSFTM and IPCW methods were implemented.
Conclusions
Inadequate reporting on the application of switching adjustment methods increases uncertainty around results, which may contribute to the limited acceptance of these methods by decision makers. The proposed reporting recommendations aim to support the improved interpretation of analyses undertaken to adjust for treatment switching
The microbiome of the human lower airways : a next generation sequencing perspective
Abstract
For a long time, the human lower airways were considered a sterile environment where the presence of microorganisms, typically revealed by culturing, was interpreted as an abnormal health state. More recently, high-throughput sequencing-based studies have led to a shift in this perception towards the notion that even in healthy conditions the lower airways show either transient presence or even permanent colonization by microorganisms. However, challenges related to low biomass and contamination in samples still remain, and the composition, structure and dynamics of such putative microbial communities are unclear. Here, we review the evidence for the presence of microbial communities in the human lower airways, in healthy subjects and within the context of medical conditions of interest. We also provide an overview of the methodology pertinent to high-throughput sequencing studies, specifically those based on amplicon sequencing, including a discussion of good practices and common pitfalls
194: A molecular profile of endothelial cell-derived growth factors that regulate stem cell self-renewal
Perceived frailty and measured frailty among adults undergoing hemodialysis: A cross-sectional analysis
10.1186/s12877-015-0051-yBMC Geriatrics1515
Prizes for basic research: Human capital, economic might and the shadow of history
Global economic trends, Basic research, Human capital, Winner-takes-all, F15, F21, O3, N4,