Fast-track versus long-term hospitalizations for patients with non-disabling acute ischaemic stroke.

BACKGROUND AND PURPOSE: The aim was to assess the feasibility and safety of fast-track hospitalizations in a selected cohort of patients with stroke. METHODS: Patients hospitalized at the Stroke Center of the University Hospital Basel, Switzerland, with an acute ischaemic stroke confirmed on magnetic resonance diffusion-weighted imaging were included. Neurological deficits of the included patients were non-disabling, i.e. not interfering with activities of daily living and compatible with a direct discharge home. Patients with premorbid disability were excluded. All patients were admitted to the Stroke Center for ≥24 h. Two study groups were compared - fast-track hospitalizations (≤72 h) and long-term hospitalizations (>72 h). The primary end-point was a composite of any unplanned rehospitalization for any reason within 3 months since hospital discharge and a modified Rankin Scale 3-6 at 3 months. Adjustment for confounders was done using the inverse probability of treatment weights (IPTW). RESULTS: Amongst the 521 patients who met the inclusion criteria, fast-track hospitalizations were performed in 79 patients (15%). In the fast-track group, seven patients (8.9%) met the primary end-point, compared to 37 (8.4%) in the long-term group [odds ratio (OR) 1.06, 95% confidence interval (CI) 0.42-2.34, P = 0.88]. After weighting for IPTW, the odds of the primary end-point remained similar between the two arms (ORIPTW 1.27, 95% CI 0.51-3.16, P = 0.61). The costs of fast-track hospitalizations were lower, on average, by $4994. CONCLUSIONS: Fast-track hospitalizations including a full workup proved to be feasible, showed no increased risk and were less expensive than long-term hospitalizations.

Dual targeting improves capture of ultrasound microbubbles towards activated platelets but yields no additional benefit for imaging of arterial thrombosis.

Platelets can be found on the surface of inflamed and ruptured atherosclerotic plaques. Thus, targeting of activated platelets may allow for molecular imaging of vulnerable atherosclerotic lesions. We here investigated microbubbles (MB) functionalized with the selectin ligand sialyl Lewisa individually (MBsLea) or dually with sLea and an antibody targeting ligand-induced binding sites of the activated GPIIb/IIIa receptor (MBDual). Assessed by in vitro flow chamber, targeted MB exhibited increased adhesion to platelets as compared to MBControl. While MBsLea rolled slowly on the platelets' surface, MBDual enhanced the percentage of firm adhesion. In vivo, MB were investigated by ultrasound in a model of ferric chloride induced non-occlusive carotid artery thrombosis. MBsLea and MBDual revealed a higher ultrasound mean acoustic intensity than MBControl (p < 0.05), however MBDual demonstrated no additional increase in mean signal intensity as compared to MBsLea. The degree of carotid artery stenosis on histology correlated well with the ultrasound acoustic intensity of targeted MB (p < 0.05). While dual targeting of MB using fast binding carbohydrate polymers and specific antibodies is a promising strategy to support adhesion to activated platelets under arterial shear stress, these advantages seem not readily translatable to in vivo models.

Diversity in livestock resources in pastoral systems in Africa.

Pastoral systems are important producers and repositories of livestock diversity. Pastoralists use variability in their livestock resources to manage high levels of environmental variability in economically advantageous ways. In pastoral systems, human-animal-environment interactions are the basis of production and the key to higher productivity and efficiency. In other words, pastoralists manage a production system that exploits variability and keeps production costs low. When differentiating, characterising and evaluating pastoral breeds, this context-specific, functional dimension of diversity in livestock resources needs to be considered. The interaction of animals with their environment is determined not only by morphological and physiological traits but also by experience and socially learned behaviour. This high proportion of non-genetic components determining the performance of livestock means that current models for analysing livestock diversity and performance, which are based on genetic inheritance, have limited ability to describe pastoral performance. There is a need for methodological innovations to evaluate pastoral breeds and animals, since comparisons based on performance 'under optimal conditions' are irrelevant within this production system. Such innovations must acknowledge that livestock or breed performance is governed by complex human-animal-environment interactions, and varies through time and space due to the mobile and seasonal nature of the pastoral system. Pastoralists' breeding concepts and selection strategies seem to be geared towards improving their animals' capability to exploit variability, by - among other things - enhancing within-breed diversity. In-depth studies of these concepts and strategies could contribute considerably towards developing methodological innovations for the characterisation and evaluation of pastoral livestock resources.

Les systèmes pastoraux sont des facteurs importants de la production et la conservation de la diversité du bétail. La variabilité des ressources d'élevage est utilisée par les pasteurs pour s'adapter à la forte variabilité environnementale de manière économiquement rentable. Dans les systèmes pastoraux, les interactions humains­animaux­environnement constituent la base de la production et un facteur déterminant d'amélioration de la productivité et du rendement. En d'autres termes, le système de production pastoral exploite la variabilité et maintient les coûts de production à un niveau faible. Cette dimension à la fois dépendante du contexte et fonctionnelle de la diversité des ressources d'élevage doit être prise en compte au moment d'identifier, de caractériser et d'évaluer les races du cheptel pastoral. L'interaction des animaux avec leur environnement n'est pas seulement déterminée par des caractéristiques morphologiques et physiologiques ; l'expérience et les comportements acquis par le groupe entrent aussi en ligne de compte. Étant donné qu'une grande partie des performances du bétail est déterminée par des composantes non génétiques, les modèles actuels d'analyse de la diversité et des performances du bétail, qui reposent sur le patrimoine génétique, sont peu pertinents pour décrire les performances du pastoralisme. Des méthodes innovantes d'évaluation du cheptel pastoral à l'échelle des races et des animaux individuels doivent être proposées, car les comparaisons classiques, basées sur les paramètres de production « dans des conditions optimales ¼ sont peu pertinentes au regard de ce système de production. Ces innovations devront tenir compte du fait que les performances du bétail ou d'une race sont fonction d'interactions complexes animaux­humains­environnement et qu'elles varient dans le temps et l'espace en raison de la nature mobile et saisonnière du système pastoral. Les stratégies et les concepts de sélection pastoraux semblent axés sur l'amélioration des capacités des animaux à exploiter la variabilité, notamment (mais non exclusivement) en améliorant la diversité au sein d'une même race. Des études approfondies de ces concepts et stratégies seraient utiles pour mettre au point des innovations méthodologiques permettant de caractériser et d'évaluer les ressources de l'élevage pastoral.

Los sistemas pastorales son importantes generadores y depositarios de diversidad ganadera. Los pastores se sirven de la variabilidad de sus recursos ganaderos para lidiar con niveles elevados de variabilidad ambiental de manera económicamente provechosa. En los sistemas de pastoreo, las interacciones del ser humano, el animal y el medio natural constituyen la base de la producción y la clave para lograr mayores cotas de productividad y eficiencia. Dicho de otro modo: el pastoreo gestiona un sistema productivo que explota la variabilidad y mantiene bajos los costos de producción. A la hora de diferenciar, caracterizar y evaluar las razas pastorales hay que tener en cuenta esta dimensión funcional, y dependiente del contexto, de la diversidad de los recursos ganaderos. La interacción de los animales con el medio natural viene dictada no solo por sus rasgos morfológicos y fisiológicos, sino también por la experiencia y el comportamiento socialmente adquirido. Esta elevada proporción de componentes no genéticos que determinan el rendimiento ganadero significa que los modelos actuales para analizar la diversidad y el rendimiento del ganado, basados en el patrimonio genético, resultan de poca utilidad para describir el funcionamiento del pastoreo. Hacen falta innovaciones metodológicas para evaluar las razas y ejemplares que son objeto de pastoreo, puesto que las comparaciones basadas en el rendimiento «en condiciones óptimas¼ no son aplicables a este tipo de sistema productivo. Tales innovaciones deben partir de la comprensión de que el rendimiento del ganado o de las razas se rige por complejas interacciones entre el hombre, los animales y el medio natural y varía en el tiempo y el espacio debido a la naturaleza itinerante y estacional que es propia del sistema pastoral. Los conceptos de cría y los procedimientos de selección de razas de las sociedades de pastores parecen ir dirigidos a conferir a sus animales mayor capacidad para explotar la variabilidad, entre otras cosas mejorando la diversidad interna de las razas. El estudio pormenorizado de tales conceptos y procedimientos podría resultar considerablemente útil para alumbrar innovaciones metodológicas destinadas a caracterizar y evaluar los recursos ganaderos pastorales.

Intra-operative assessment of pulmonary artery pressure by transoesophageal echocardiography.

The clinical value of the estimation of systolic pulmonary artery pressure, based on Doppler assessment of peak tricuspid regurgitant velocity using transoesophageal echocardiography, is unclear. We studied 109 patients to evaluate the feasibility of obtaining adequate Doppler recordings, and compared Doppler estimates with values measured using a pulmonary artery catheter in a subset of 33 patients. Tricuspid regurgitation was evaluated at the mid-oesophageal level at 0-120° using Doppler echocardiography. A Doppler signal was defined as adequate if there was a ≤ 20° alignment and a full envelope. Doppler estimates of systolic pulmonary artery pressure within 10 mmHg and 15% of the value recorded with the pulmonary artery catheter were considered to be in sufficient agreement. Adequate Doppler signals were obtained in 64/109 (59%) patients before and 54/103 (52%) after surgery. Doppler estimates by transoesophageal echocardiography were within 10 mmHg and 15% of values recorded with the pulmonary artery catheter in 28/33 (75%) patients and 22/31 (55%) patients, respectively. In 7 (21%) patients, the echocardiographic Doppler measurement exceeded the measured systolic pulmonary artery pressure by more than 30%. Our study indicates that estimation of the systolic pulmonary artery pressure using transoesophageal Doppler echocardiography is not a reliable and clinically useful method in anaesthetised patients undergoing mechanical ventilation.

Evidence supportive of impaired myocardial blood flow reserve at high altitude in subjects developing high-altitude pulmonary edema.

An exaggerated increase in pulmonary arterial pressure is the hallmark of high-altitude pulmonary edema (HAPE) and is associated with endothelial dysfunction of the pulmonary vasculature. Whether the myocardial circulation is affected as well is not known. The aim of this study was, therefore, to investigate whether myocardial blood flow reserve (MBFr) is altered in mountaineers developing HAPE. Healthy mountaineers taking part in a trial of prophylactic treatment of HAPE were examined at low (490 m) and high altitude (4,559 m). MBFr was derived from low mechanical index contrast echocardiography, performed at rest and during submaximal exercise. Among 24 subjects evaluated for MBFr, 9 were HAPE-susceptible individuals on prophylactic treatment with dexamethasone or tadalafil, 6 were HAPE-susceptible individuals on placebo, and 9 persons without HAPE susceptibility served as controls. At low altitude, MBFr did not differ between groups. At high altitude, MBFr increased significantly in HAPE-susceptible individuals on treatment (from 2.2 +/- 0.8 at low to 2.9 +/- 1.0 at high altitude, P = 0.04) and in control persons (from 1.9 +/- 0.8 to 2.8 +/- 1.0, P = 0.02), but not in HAPE-susceptible individuals on placebo (2.5 +/- 0.3 and 2.0 +/- 1.3 at low and high altitude, respectively, P > 0.1). The response to high altitude was significantly different between the two groups (P = 0.01). There was a significant inverse relation between the increase in the pressure gradient across the tricuspid valve and the change in myocardial blood flow reserve. HAPE-susceptible individuals not taking prophylactic treatment exhibit a reduced MBFr compared with either treated HAPE-susceptible individuals or healthy controls at high altitude.

Stunning and left ventricular function--how long is the ventricle knocked out? Left ventricular function correlated with ischemic burden and recovery time after stress.

PURPOSE: Little is known about the relation between severity of ischemia and duration of myocardial stunning. The aim of this study was therefore to characterize the impact of ischemia on myocardial stunning and on its duration. METHODS: 310 patients (pts) who underwent myocardial perfusion SPECT (MPS) were evaluated. MPS acquired with a rest Thallium/stress Technetium-99m sestamibi protocol were scored with respect to % myocardium ischemic. Left ventricular post-stress ejection fraction (psEF) was evaluated by the widely used QGS algorithm. Resting LVEF (rEF) was assessed by invasive ventriculography. Patient groups were then compared with respect to different extents of ischemia and different time intervals between stress and imaging (< or = 60 min and > 60 min after stress). RESULTS: 21% of pts had a normal MPS, 8% had evidence of scar, 37% had evidence of ischemia, and 34% had evidence of scar plus ischemia. Pts with normal MPS had a significantly higher psEF than pts with ischemia, 61+/-8% and 56+/-8%, respectively (p=0.006), whereas rEF was not different. Overall, pts with < or = 10% myocardium ischemic had significantly higher psEF than pts with > 10% myocardium ischemic, 53+/-11% and 49+/-9%, respectively (p=0.006), whereas rEF was not different. In pts with evidence of ischemia who underwent imaging < or = 60 min after stress testing, pts with < or = 10% myocardium ischemic had higher psEF than pts with > 10% myocardium ischemic, 60+/-7% and 53+/-8%, respectively (p=0.037). In contrast, pts with evidence of ischemia who underwent imaging > 60 min after stress testing had similar psEF irrespective of extent of ischemia (53%+/-8 in pts with < or = 10% ischemia and 54%+/-8 in pts with > 10% myocardium ischemic, p=0.12). CONCLUSIONS: Ischemia had a significant impact on psEF in patients who underwent imaging less than 1 h after stress. More than one hour after stress testing stunning seems to be less relevant in the interpretation of psEF.