Extracorporeal membrane oxygenation support in acardia.

In extreme situations, such as hyperacute rejection of heart transplant or major heart trauma, heart preservation may not be possible. Our experimental team works on a project of peripheral extracorporeal membrane oxygenation (ECMO) support in acardia as a bridge to heart transplantation or artificial heart implantation. An ECMO support was established in five calves (58.6 ± 6.9 kg) by the transjugular insertion to the caval axis of a self-expanded cannula, with carotid artery return. After baseline measurements, ventricular fibrillation was induced, great arteries were clamped, heart was excised, and right and left atria remnants, containing pulmonary veins, were sutured together leaving an atrial septal defect over the caval axis cannula. Measurements of pump flow and arterial pressure were taken with the pulmonary artery clamped and anastomosed with the caval axis for a total of 6 hours. Pulmonary artery anastomosis to the caval axis provided an acceptable 6 hour hemodynamic stability, permitting a peripheral access ECMO support in extreme scenarios indicating a heart explantation.

Embolisation hémostatique des hématomes spontanés musculaires abdomino-pelviens.

Objectifs: Etudier les résultats techniques et cliniques de l'embolisation des hématomes musculaires spontanés de l'abdomen . Caractériser les hématomes ayant étéembolisés au CT et définir les éventuels critères cliniques et anatomiques pour une embolisation . Etudier la relation entre les hématomes embolisés et lesanticoagulants.Matériels et méthodes: Etude rétrospective des patients ayant bénéficié d'une embolisation pour un hématome musculaire abdominopelvien spontané entre 2005 et 2010. Sont analysésles données cliniques (anticaogulants, retentissement hémodynamqiue), les données scanographiques (site, volume, saignement actif), les artères embolisées etle type d'embol, le résultat clinique immédiat, les complications et la mortalité en cours d'hospitalisation .Résultats: 28 patients (âge moyen 75 ans) ont été embolisés. Tous les patients avaient un traitement anticoagulant et/ou antiplaquettaire. La majorité des hématomesembolisés concernaient le muscle grand droit de l'abdomen. Le saignement actif n'était pas identifié chez tous les patients au CT. Pas de complication immédiaterapportée. Le succès technique était de 98%. Pas de récidive précoce rapportée y compris après réintroduction du traitement anticaogulant.Conclusion: L'embolisation hémostatique des hématomes musculaires spontanés sous anticoagulants est efficace pour contrôler le saignement et permettre la réintroductiondu traitement anticoagulant.

Positive control of swarming, rhamnolipid synthesis, and lipase production by the posttranscriptional RsmA/RsmZ system in Pseudomonas aeruginosa PAO1.

In Pseudomonas aeruginosa, the small RNA-binding, regulatory protein RsmA is a negative control element in the formation of several extracellular products (e.g., pyocyanin, hydrogen cyanide, PA-IL lectin) as well as in the production of N-acylhomoserine lactone quorum-sensing signal molecules. RsmA was found to control positively the ability to swarm and to produce extracellular rhamnolipids and lipase, i.e., functions contributing to niche colonization by P. aeruginosa. An rsmA null mutant was entirely devoid of swarming but produced detectable amounts of rhamnolipids, suggesting that factors in addition to rhamnolipids influence the swarming ability of P. aeruginosa. A small regulatory RNA, rsmZ, which antagonized the effects of RsmA, was identified in P. aeruginosa. Expression of the rsmZ gene was dependent on both the global regulator GacA and RsmA, increased with cell density, and was subject to negative autoregulation. Overexpression of rsmZ and a null mutation in rsmA resulted in quantitatively similar, negative or positive effects on target genes, in agreement with a model that postulates titration of RsmA protein by RsmZ RNA.

MP2RAGE, a self bias-field corrected sequence for improved segmentation and T-1-mapping at high field

The large spatial inhomogeneity in transmit B, field (B-1(+)) observable in human MR images at hi h static magnetic fields (B-0) severely impairs image quality. To overcome this effect in brain T-1-weighted images the, MPRAGE sequence was modified to generate two different images at different inversion times MP2RAGE By combining the two images in a novel fashion, it was possible to create T-1-weigthed images where the result image was free of proton density contrast, T-2* contrast, reception bias field, and, to first order transmit field inhomogeneity. MP2RAGE sequence parameters were optimized using Bloch equations to maximize contrast-to-noise ratio per unit of time between brain tissues and minimize the effect of B-1(+) variations through space. Images of high anatomical quality and excellent brain tissue differentiation suitable for applications such as segmentation and voxel-based morphometry were obtained at 3 and 7 T. From such T-1-weighted images, acquired within 12 min, high-resolution 3D T-1 maps were routinely calculated at 7 T with sub-millimeter voxel resolution (0.65-0.85 mm isotropic). T-1 maps were validated in phantom experiments. In humans, the T, values obtained at 7 T were 1.15 +/- 0.06 s for white matter (WM) and 1.92 +/- 0.16 s for grey matter (GM), in good agreement with literature values obtained at lower spatial resolution. At 3 T, where whole-brain acquisitions with 1 mm isotropic voxels were acquired in 8 min the T-1 values obtained (0.81 +/- 0.03 S for WM and 1.35 +/- 0.05 for GM) were once again found to be in very good agreement with values in the literature. (C) 2009 Elsevier Inc. All rights reserved.

BOLD responses to trigeminal nerve stimulation.

The current study investigates a new model of barrel cortex activation using stimulation of the infraorbital branch of the trigeminal nerve. A robust and reproducible activation of the rat barrel cortex was obtained following trigeminal nerve stimulation. Blood oxygen level-dependent (BOLD) effects were obtained in the primary somatosensory barrel cortex (S1BF), the secondary somatosensory cortex (S2) and the motor cortex. These cortical areas were reached from afferent pathways from the trigeminal ganglion, the trigeminal nuclei and thalamic nuclei from which neurons project their axons upon whisker stimulation. The maximum BOLD responses were obtained for a stimulus frequency of 1 Hz, a stimulus pulse width of 100 μs and for current intensities between 1.5 and 3 mA. The BOLD response was nonlinear as a function of frequency and current intensity. Additionally, modeling BOLD responses in the rat barrel cortex from separate cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO(2)) measurements showed good agreement with the shape and amplitude of measured BOLD responses as a function of stimulus frequency and will potentially allow to identify the sources of BOLD nonlinearities. Activation of the rat barrel cortex using trigeminal nerve stimulation will contribute to the interpretation of the BOLD signals from functional magnetic resonance imaging studies.

Coronary sinus atresia with persistent left superior vena cava: unusual clinical presentation and endovascular management.

Atresia of the coronary sinus (ACS) is a rare congenital anomaly. When associated with persistent left superior vena cava (PLSVC), this defect could have no significant hemodynamic effect, and the patient might remain asymptomatic. However, vascular interventions might induce changes or complications that could show the anomaly. Appropriate management requires a good understanding of this condition. We present the first reported case of ACS and PLSVC occurring after thrombosis of the innominate vein (IV) after central venous catheter placement. The patient presented with atypical subacute chest pain and recurrent extrasystoles. Diagnosis and characterization of vascular anomalies was made by computed tomography phlebography, and the patient was successfully managed by endovascular recanalization of the IV.

Biotechnology to improve health in developing countries: a review

The growing health disparities between the developing and the developed world call for urgent action from the scientific community. Science and technology have in the past played a vital role in improving public health. Today, with the tremendous potential of genomics and other advances in the life sciences, the contribution of science to improve public health and reduce global health disparities is more pertinent than ever before. Yet the benefits of modern medicine still have not reached millions of people in developing countries. It is crucial to recognize that science and technology can be used very effectively in partnership with public health practices in developing countries and can enhance their efficacy. The fight to improve global health needs, in addition to effective public health measures, requires rapid and efficient diagnostic tools; new vaccines and drugs, efficient delivery methods and novel approaches to therapeutics; and low-cost restoration of water, soil and other natural resources. In 2002, the University of Toronto published a report on the "Top 10 Biotechnologies for Improving Health in Developing Countries". Here we review these new and emerging biotechnologies and explore how they can be used to support the goals of developing countries in improving health.

Direct in vivo measurement of glycine and the neurochemical profile in the rat medulla oblongata.

The medulla oblongata (MO) contains a high density of glycinergic synapses and a particularly high concentration of glycine. The aims of this study were to measure directly in vivo the neurochemical profile, including glycine, in MO using a spin-echo-based (1)H MRS sequence at TE?=?2.8 ms and to compare it with three other brain regions (cortex, striatum and hippocampus) in the rat. Glycine was quantified in MO at TE?=?2.8 ms with a Cramér-Rao lower bound (CRLB) of approximately 5%. As a result of the relatively low level of glycine in the other three regions, the measurement of glycine was performed at TE?=?20 ms, which provides a favorable J-modulation of overlapping myo-inositol resonance. The other 14 metabolites composing the neurochemical profile were quantified in vivo in MO with CRLBs below 25%. Absolute concentrations of metabolites in MO, such as glutamate, glutamine, ?-aminobutyrate, taurine and glycine, were in the range of previous in vitro quantifications in tissue extracts. Compared with the other regions, MO had a three-fold higher glycine concentration, and was characterised by reduced (p?<?0.001) concentrations of glutamate (-50?±?4%), glutamine (-54?±?3%) and taurine (-78?±?3%). This study suggests that the functional specialisation of distinct brain regions is reflected in the neurochemical profile.

Analysis of angiotensin II- and ACTH-driven mineralocorticoid functions and omental adiposity in a non-genetic, hyperadipose female rat phenotype

The hypothalamic damage induced by neonatal treatment with monosodium l-glutamate (MSG) induces several metabolic abnormalities, resulting in a rat hyperleptinemic-hyperadipose phenotype. This study was conducted to explore the impact of the neonatal MSG treatment, in the adult (120 days old) female rat on: (a) the in vivo and in vitro mineralocorticoid responses to ACTH and angiotensin II (AII); (b) the effect of leptin on ACTH- and AII-stimulated mineralocorticoid secretions by isolated corticoadrenal cells; and (c) abdominal adiposity characteristics. Our data indicate that, compared with age-matched controls, MSG rats displayed: (1) enhanced and reduced mineralocorticoid responses to ACTH and AII treatments, respectively, effects observed in both in vivo and in vitro conditions; (2) adrenal refractoriness to the inhibitory effect of exogenous leptin on ACTH-stimulated aldosterone output by isolated adrenocortical cells; and (3) distorted omental adiposity morphology and function. This study supports that the adult hyperleptinemic MSG female rat is characterized by enhanced ACTH-driven mineralocorticoid function, impaired adrenal leptin sensitivity, and disrupted abdominal adiposity function. MSG rats could counteract undesirable effects of glucocorticoid excess, by developing a reduced AII-driven mineralocorticoid function. Thus, chronic hyperleptinemia could play a protective role against ACTH-mediated allostatic loads in the adrenal leptin resistant, MSG female rat phenotype.

Case report: an unusual combined retrograde and antegrade transpedal subintimal recanalization of the infrainguinal arteries.

Retrograde or combined retrograde and antegrade recanalization should be considered when antegrade recanalization has failed in selected patients with critical limb ischemia (CLI). Retrograde recanalization is typically attempted through a patent segment of the popliteal artery or an infrapopliteal artery. The challenge arises, however, when there are no patent popliteal or infrapopliteal arteries suitable for retrograde access.

Management of bleeding following major trauma: a European guideline

INTRODUCTION Evidence-based recommendations can be made with respect to many aspects of the acute management of the bleeding trauma patient, which when implemented may lead to improved patient outcomes. METHODS The multidisciplinary Task Force for Advanced Bleeding Care in Trauma was formed in 2005 with the aim of developing guidelines for the management of bleeding following severe injury. Recommendations were formulated using a nominal group process and the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) hierarchy of evidence and were based on a systematic review of published literature. RESULTS Key recommendations include the following: The time elapsed between injury and operation should be minimised for patients in need of urgent surgical bleeding control, and patients presenting with haemorrhagic shock and an identified source of bleeding should undergo immediate surgical bleeding control unless initial resuscitation measures are successful. A damage control surgical approach is essential in the severely injured patient. Pelvic ring disruptions should be closed and stabilised, followed by appropriate angiographic embolisation or surgical bleeding control, including packing. Patients presenting with haemorrhagic shock and an unidentified source of bleeding should undergo immediate further assessment as appropriate using focused sonography, computed tomography, serum lactate, and/or base deficit measurements. This guideline also reviews appropriate physiological targets and suggested use and dosing of blood products, pharmacological agents, and coagulation factor replacement in the bleeding trauma patient. CONCLUSION A multidisciplinary approach to the management of the bleeding trauma patient will help create circumstances in which optimal care can be provided. By their very nature, these guidelines reflect the current state-of-the-art and will need to be updated and revised as important new evidence becomes available.

Myxoma on a mechanical mitral valve annulus.

To date, myxoma on a mechanical valve annulus has not been reported. The case is reported of a 74-year-old woman who was admitted to hospital following the identification of an intracardiac tumor mass. Six years previously, the patient had received a mechanical valve implanted in the mitral position. Transesophageal echocardiography revealed a mobile hypoechogenic tumorous mass attached to the anterior annulus of the prosthesis. The tumor was successfully treated by surgical excision, and a diagnosis of myxoma was confirmed both clinically and pathologically.

Comparison of topography- and aperture-dependent motion compensation algorithms for airborne SAR

This letter presents a comparison between threeFourier-based motion compensation (MoCo) algorithms forairborne synthetic aperture radar (SAR) systems. These algorithmscircumvent the limitations of conventional MoCo, namelythe assumption of a reference height and the beam-center approximation.All these approaches rely on the inherent time–frequencyrelation in SAR systems but exploit it differently, with the consequentdifferences in accuracy and computational burden. Aftera brief overview of the three approaches, the performance ofeach algorithm is analyzed with respect to azimuthal topographyaccommodation, angle accommodation, and maximum frequencyof track deviations with which the algorithm can cope. Also, ananalysis on the computational complexity is presented. Quantitativeresults are shown using real data acquired by the ExperimentalSAR system of the German Aerospace Center (DLR).

[Palette des couleurs]. VIIII : [version "terre rouge"] : [estampe] / [gravé sous la direction de Jacob Christoph Le Blon]

Référence bibliographique : Singer, 46