Cost evaluation of cardiac magnetic resonance imaging versus coronary angiography for the work-up of coronary artery disease

Background: CMR has recently emerged as a robust and reliable technique to assess coronary artery disease (CAD). A negative perfusion CMR test predicts low event rates of 0.3-0.5%/year. Invasive coronary angiography (CA) remains the "gold standard" for the evaluation of CAD in many countries.Objective: Assessing the costs of the two strategies in the European CMR registry for the work-up of known or suspected CAD from a health care payer perspective. Strategy 1) a CA to all patients or 2) a CA only to patients who are diagnosed positive for ischemia in a prior CMR.Method and results: Using data of the European CMR registry (20 hospitals, 11'040 consecutive patients) we calculated the proportion of patients who were diagnosed positive (20.6%), uncertain (6.5%), and negative (72.9%) after the CMR test in patients with known or suspected CAD (n=2'717). No other medical test was performed to patients who were negative for ischemia. Positive diagnosed patients had a coronary angiography. Those with uncertain diagnosis had additional tests (84.7%: stress echocardiography, 13.1%: CCT, 2.3% SPECT), these costs were added to the CMR strategy costs. Information from costs for tests in Germany and Switzerland were used. A sensibility analysis was performed for inpatient CA. For costs see figure. Results - costs.Discussion: The CMR strategy costs less than the CA strategy for the health insurance systems both, in Germany and Switzerland. While lower in costs, the CMR strategy is a non-invasive one, does not expose to radiation, and yields additional information on cardiac function, viability, valves, and great vessels. Developing the use of CMR instead of CA might imply some reduction in costs together with superior patient safety and comfort, and a better utilization of resources at the hospital level. Document introduit le : 01.12.2011

Agglutinating Secretory IgA Preserves Intestinal Epithelial Cell Integrity during Apical Infection by Shigella flexneri.

Shigella flexneri, by invading intestinal epithelial cells (IECs) and inducing inflammatory responses of the colonic mucosa, causes bacillary dysentery. Although M cells overlying Peyer's patches are commonly considered the primary site of entry of S. flexneri, indirect evidence suggests that bacteria can also use IECs as a portal of entry to the lamina propria. Passive delivery of secretory IgA (SIgA), the major immunoglobulin secreted at mucosal surfaces, has been shown to protect rabbits from experimental shigellosis, but no information exists as to its molecular role in maintaining luminal epithelial integrity. We have established that the interaction of virulent S. flexneri with the apical pole of a model intestinal epithelium consisting of polarized Caco-2 cell monolayers resulted in the progressive disruption of the tight junction network and actin depolymerization, eventually resulting in cell death. The lipopolysaccharide (LPS)-specific agglutinating SIgAC5 monoclonal antibody (MAb), but not monomeric IgAC5 or IgGC20 MAbs of the same specificity, achieved protective functions through combined mechanisms, including limitation of the interaction between S. flexneri and epithelial cells, maintenance of the tight junction seal, preservation of the cell morphology, reduction of NF-κB nuclear translocation, and inhibition of proinflammatory mediator secretion. Our results add to the understanding of the function of SIgA-mediated immune exclusion by identifying a mode of action whereby the formation of immune complexes translates into maintenance of the integrity of epithelial cells lining the mucosa. This novel mechanism of protection mediated by SIgA is important to extend the arsenal of effective strategies to fight against S. flexneri mucosal invasion.

Atypical teratoid/rhabdoid tumor of the spine in a 4-year-old girl.

Primary spinal atypical teratoid/rhabdoid tumor is extremely rare. The authors present a case of atypical teratoid/rhabdoid tumor occurring in a 4-year-old girl. Magnetic resonance imaging The authors showed an intramedullary mass extending from the bulbomedullary junction to T1 with leptomeningeal dissemination. The patient died 2 weeks after diagnosis.

L'aprenentatge basat en problemes (PBL) en la regulació del metabolisme. Desenvolupament del portal per a l'intercanvi d'experiències en PBL en ciències biomèdiques

L’aprenentatge basat en problemes està en fase experimental en tot el món i és objecte d’anàlisi i reflexió en moltes reunions internacionals. Tanmateix, no hi ha massa feina feta en aquesta direcció en el nostre camp més proper. Hem elaborat problemes per l’aprenentatge de la Regulació del Metabolisme i els hem incorporat a un porta virtual (http://www.ub.edu/GID-BBM). La finalitat d’aquesta estratègia és que mitjançant l’aprenentatge basat en problemes reals o simulacions de problemes reals s’aconsegueixi motivar l’alumnat a treballar de forma continuada durant tot el curs. La millora dels resultats acadèmics haurà de ser la conseqüència lògica d’aquest treball. La finalitat última del projecte que hem desenvolupat és preparar l’alumnat per la seva futura activitat professional a on serà molt important i valorat la seva capacitat de resposta davant de diferents problemes

Functional mapping of the human visual cortex with intravoxel incoherent motion MRI.

Functional imaging with intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) is demonstrated. Images were acquired at 3 Tesla using a standard Stejskal-Tanner diffusion-weighted echo-planar imaging sequence with multiple b-values. Cerebro-spinal fluid signal, which is highly incoherent, was suppressed with an inversion recovery preparation pulse. IVIM microvascular perfusion parameters were calculated according to a two-compartment (vascular and non-vascular) diffusion model. The results obtained in 8 healthy human volunteers during visual stimulation are presented. The IVIM blood flow related parameter fD* increased 170% during stimulation in the visual cortex, and 70% in the underlying white matter.

Implementació d'un Laboratori Virtual d'Equips Electrònics per múltiples aplicacions específiqies com a reforç docent en l'àrea de l'electrònica VERiLAB (Virtual ElectRonic LABoratory)

S’ha dissenyat un Laboratori Virtual d’Equips Electrònics per múltiples aplicacions específiques com a reforç docent en l’àrea de l’electrònica VERiLAB (Virtual ElectRonic LABoratory) i, a més, s’han dissenyat un conjunt de 9 pràctiques guiades per treure el màxim rendiment al laboratori virtual. El laboratori Virtual és una potent eina de treball per aplicacions docents com a programari d’iniciació a la utilització d’equips electrònics bàsics que podem trobar a qualsevol laboratori d’electrònica. Aquesta eina permet augmentar el nombre d’hores de treball pràctic fora del laboratori. La primera versió d’aquest programari es va dissenyar a l’any 2004 a la Universitat de Barcelona amb el software LabVIEW_7, el qual permet obtenir un fitxer executable amb el qual els alumnes poden treballar fora del laboratori. D’aquesta forma els alumnes únicament necessiten un ordinador per a poder fer les pràctiques. La primera versió del laboratori disposava d’un generador de funcions, un oscil·loscopi i un analitzador d’espectres com a equips electrònics, i a més a més incorporava un mòdul de filtres i un motor DC per treballar amb els equips. La versió 2 del Laboratori Virtual es va desenvolupar amb aquest projecte MQD i es va introduir una font d’alimentació, un multímetre de sobre taula i un portàtil com a equips electrònics. Es van crear també diferents mòduls de sistemes electrònics: filtres analògics, configuracions bàsiques basades en l’amplificador operacional, l’amplificador operacional no ideal i un circuit de rectificació d’ona completa. Aquests mòduls han premés ampliar el camp d’aplicació del Laboratori Virtual a diferents assignatures de l’àrea de l’electrònica.

Magnetic resonance-guided, real-time targeted delivery and imaging of magnetocapsules immunoprotecting pancreatic islet cells.

In type I diabetes mellitus, islet transplantation provides a moment-to-moment fine regulation of insulin. Success rates vary widely, however, necessitating suitable methods to monitor islet delivery, engraftment and survival. Here magnetic resonance-trackable magnetocapsules have been used simultaneously to immunoprotect pancreatic beta-cells and to monitor, non-invasively in real-time, hepatic delivery and engraftment by magnetic resonance imaging (MRI). Magnetocapsules were detected as single capsules with an altered magnetic resonance appearance on capsule rupture. Magnetocapsules were functional in vivo because mouse beta-cells restored normal glycemia in streptozotocin-induced diabetic mice and human islets induced sustained C-peptide levels in swine. In this large-animal model, magnetocapsules could be precisely targeted for infusion by using magnetic resonance fluoroscopy, whereas MRI facilitated monitoring of liver engraftment over time. These findings are directly applicable to ongoing improvements in islet cell transplantation for human diabetes, particularly because our magnetocapsules comprise clinically applicable materials.

Growing up with bilateral hippocampal atrophy: from childhood to teenage.

The respective roles of the medial temporal lobe (MTL) structures in memory are controversial. Some authors put forward a modular account according to which episodic memory and recollection-based processes are crucially dependent on the hippocampal formation whereas semantic acquisition and familiarity-based processes rely on the adjacent parahippocampal gyri. Others defend a unitary view. We report the case of VJ, a boy with developmental amnesia of most likely perinatal onset diagnosed at the age of 8. Magnetic resonance imaging (MRI), including quantitative volumetric measurements of the hippocampal formation and of the entorhinal, perirhinal, and temporopolar cortices, showed severe, bilateral atrophy of the hippocampal formation, fornix and mammillary bodies; by contrast, the perirhinal cortex was within normal range and the entorhinal and temporopolar cortex remained within two standard deviations (SDs) from controls' mean. We examined the development of his semantic knowledge from childhood to teenage as well as his recognition and cued recall memory abilities. On tasks tapping semantic memory, VJ increased his raw scores across years at the same rate as children from large standardisation samples, except for one task; he achieved average performance, consistent with his socio-educational background. He performed within normal range on 74% of recognition tests and achieved average to above average scores on 42% of them despite very severe impairment on 82% of episodic recall tasks. Both faces and landscapes-scenes gave rise to above average scores when tested with coloured stimuli. Cued recall, although impaired, was largely superior to free recall. This case supports a modular account of the MTL with episodic, but not semantic memory depending on the hippocampal formation. Furthermore, the overall pattern of findings is consistent with evidence from both brain-damaged and neuroimaging studies indicating that recollection requires intact hippocampal formation and familiarity relies, at least partly, on the adjacent temporal lobe cortex.

A protocol for preparing GFP-labeled neurons previously imaged in vivo and in slice preparations for light and electron microscopic analysis.

In vivo imaging of green fluorescent protein (GFP)-labeled neurons in the intact brain is being used increasingly to study neuronal plasticity. However, interpreting the observed changes as modifications in neuronal connectivity needs information about synapses. We show here that axons and dendrites of GFP-labeled neurons imaged previously in the live mouse or in slice preparations using 2-photon laser microscopy can be analyzed using light and electron microscopy, allowing morphological reconstruction of the synapses both on the imaged neurons, as well as those in the surrounding neuropil. We describe how, over a 2-day period, the imaged tissue is fixed, sliced and immuno-labeled to localize the neurons of interest. Once embedded in epoxy resin, the entire neuron can then be drawn in three dimensions (3D) for detailed morphological analysis using light microscopy. Specific dendrites and axons can be further serially thin sectioned, imaged in the electron microscope (EM) and then the ultrastructure analyzed on the serial images.

Calibration of surface contamination monitors for the detection of iodine incorporation in the thyroid gland.

In Switzerland, individuals exposed to the risk of activity intake are required to perform regular monitoring. Monitoring consists in a screening measurement and is meant to be performed using commonly available laboratory instruments. More particularly, iodine intake is measured using a surface contamination monitor. The goal of the present paper is to report the calibration method developed for thyroid screening instruments. It consists of measuring the instrument response to a known activity located in the thyroid gland of a standard neck phantom. One issue of this procedure remains that the iodine radioisotopes have a short half-life. Therefore, the adequacy and limitations to simulate the short-lived radionuclides with so-called mock radionuclides of longer half-life were also evaluated. In light of the results, it has been decided to use only the appropriate iodine sources to perform the calibration.

Rapid, combinatorial analysis of membrane compartments in intact plants with a multicolor marker set.

Plant membrane compartments and trafficking pathways are highly complex, and are often distinct from those of animals and fungi. Progress has been made in defining trafficking in plants using transient expression systems. However, many processes require a precise understanding of plant membrane trafficking in a developmental context, and in diverse, specialized cell types. These include defense responses to pathogens, regulation of transporter accumulation in plant nutrition or polar auxin transport in development. In all of these cases a central role is played by the endosomal membrane system, which, however, is the most divergent and ill-defined aspect of plant cell compartmentation. We have designed a new vector series, and have generated a large number of stably transformed plants expressing membrane protein fusions to spectrally distinct, fluorescent tags. We selected lines with distinct subcellular localization patterns, and stable, non-toxic expression. We demonstrate the power of this multicolor 'Wave' marker set for rapid, combinatorial analysis of plant cell membrane compartments, both in live-imaging and immunoelectron microscopy. Among other findings, our systematic co-localization analysis revealed that a class of plant Rab1-homologs has a much more extended localization than was previously assumed, and also localizes to trans-Golgi/endosomal compartments. Constructs that can be transformed into any genetic background or species, as well as seeds from transgenic Arabidopsis plants, will be freely available, and will promote rapid progress in diverse areas of plant cell biology.

Periprocedural Hemodynamic Depression Is Associated With a Higher Number of New Ischemic Brain Lesions After Stenting in the International Carotid Stenting Study-MRI Substudy.

BACKGROUND AND PURPOSE: Carotid artery stenting (CAS) is associated with a higher risk of both hemodynamic depression and new ischemic brain lesions on diffusion-weighted imaging than carotid endarterectomy (CEA). We assessed whether the occurrence of hemodynamic depression is associated with these lesions in patients with symptomatic carotid stenosis treated by CAS or CEA in the randomized International Carotid Stenting Study (ICSS)-MRI substudy. METHODS: The number and total volume of new ischemic lesions on diffusion-weighted imaging 1 to 3 days after CAS or CEA was measured in the ICSS-MRI substudy. Hemodynamic depression was defined as periprocedural bradycardia, asystole, or hypotension requiring treatment. The number of new ischemic lesions was the primary outcome measure. We calculated risk ratios and 95% confidence intervals per treatment with Poisson regression comparing the number of lesions in patients with or without hemodynamic depression. RESULTS: A total of 229 patients were included (122 allocated CAS; 107 CEA). After CAS, patients with hemodynamic depression had a mean of 13 new diffusion-weighted imaging lesions, compared with a mean of 4 in those without hemodynamic depression (risk ratio, 3.36; 95% confidence interval, 1.73-6.50). The number of lesions after CEA was too small for reliable analysis. Lesion volumes did not differ between patients with or without hemodynamic depression. CONCLUSIONS: In patients treated by CAS, periprocedural hemodynamic depression is associated with an excess of new ischemic lesions on diffusion-weighted imaging. The findings support the hypothesis that hypoperfusion increases the susceptibility of the brain to embolism. CLINICAL TRIAL REGISTRATION URL: http://www.controlled-trials.com. Unique identifier: ISRCTN25337470.

Preserving Electronic Theses through the MetaArchive network

In the recent years most libraries have focused on mass digitization programs and keeping electronic born documents, showing and organizing them in a repository. While those repositories have evolved to a much more manageable systems focusing on the user expectations and introducing web 2.0 tools, digital preservation is still in the to-do list of most of them. There is quite a lot of studies focused on preservation and some complex models exist, unfortunately, very few practical systems are running and its quite difficult for a library to get involved in a solution already tested by others. The CBUC (Consortium of University Catalan Libraries) runs TDX, an ETD repository now keeping more than 10.000 full text thesis from any of the 12 university members. After 10 years running TDX a solid preservation system was needed to ensure every thesis would be kept as it was regardless what happens to the repository. The perfect solution was found in the MetaArchive cooperative, this is the effort of many insitutions to keep a copy of each other content through a newtwork using the LOCKSS software as a mechanism to keep track of any change. The presentation will shortly introduce what TDX and MetaArchive is but will, in a practical way, show how the LOCKSS network for presrervation works. Finally a summary of the benefits of the overall experience will be shown.