Angiotensin II Induces Leukocyte–Endothelial Cell Interactions In Vivo Via AT1 and AT2 Receptor–Mediated P-Selectin Upregulation

Background—Angiotensin II (Ang II) plays a critical role in the development of vascular lesions in hypertension, atherosclerosis, and several renal diseases. Because Ang II may contribute to the leukocyte recruitment associated with these pathological states, the aim of the present study was to assess the role of Ang II in leukocyte–endothelial cell interactions in vivo. Methods and Results—Intravital microscopy of the rat mesenteric postcapillary venules was used. Sixty minutes of superfusion with 1 nmol/L Ang II induced a significant increase in leukocyte rolling flux (83.8±20.7 versus 16.4±3.1 cells/min), adhesion (11.4±1.0 versus 0.8±0.5 cells/100 µm), and emigration (4.0±0.7 versus 0.2±0.2 cells/field) without any vasoconstrictor activity. These effects were not mediated by mast cell activation. Intravenous pretreatment with AT1 (losartan) or AT2 (PD123,319) receptor antagonists significantly reduced Ang II–induced responses. A combination of both receptor antagonists inhibited the leukocyte rolling flux, adhesion, and extravasation elicited by Ang II at 60 minutes. Pretreatment of animals with fucoidin or an adhesion-blocking anti–rat P-selectin monoclonal antibody abolished Ang II–induced leukocyte responses. Furthermore, rat platelet P-selectin expression was not affected by Ang II stimulation. Conclusions—Ang II induces significant leukocyte rolling, adhesion, and emigration, which may contribute not only to hypertension but also to the onset and progression of the vascular damage associated with disease states in which plasma levels of this peptide are elevated.Piqueras Ruiz, Laura, [email protected] ; Alvarez Ribelles, Angeles, [email protected] ; Esplugues Mota, Juan Vicente, [email protected] ; Sanz Ferrando, Maria Jesus, [email protected]

The value of selected in vitro and in silico methods to predict acute oral toxicity in a regulatory context: results from the European Project ACuteTox

ACuteTox is a project within the 6th European Framework Programme which had as one of its goals to develop, optimise and prevalidate a non-animal testing strategy for predicting human acute oral toxicity. In its last 6months, a challenging exercise was conducted to assess the predictive capacity of the developed testing strategies and final identification of the most promising ones. Thirty-two chemicals were tested blind in the battery of in vitro and in silico methods selected during the first phase of the project. This paper describes the classification approaches studied: single step procedures and two step tiered testing strategies. In summary, four in vitro testing strategies were proposed as best performing in terms of predictive capacity with respect to the European acute oral toxicity classification. In addition, a heuristic testing strategy is suggested that combines the prediction results gained from the neutral red uptake assay performed in 3T3 cells, with information on neurotoxicity alerts identified by the primary rat brain aggregates test method. Octanol-water partition coefficients and in silico prediction of intestinal absorption and blood-brain barrier passage are also considered. This approach allows to reduce the number of chemicals wrongly predicted as not classified (LD(50)>2000mg/kg b.w.).Peer Reviewe

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Una halocina que actúa sobre el intercambiador Na+/H+ de Haloarchaea como un nuevo tipo de inhibidor de NHE de mamíferos

10 páginas, 3 figuras.[EN]: The capability of halocin H6 (a bacteriocin-like protein produced by haloarchaeaHaloferax gibbonsii) to inhibit Na+/H+ exchange (NHE) in mammalian cells and its cardio-protective efficacy on the ischemic and reperfused myocardium were evaluated in the present study. H6 inhibits NHE activity (measured by a flow cytometry method) in a dose-dependent form of cell lines of mammalian origin (HEK293, NIH3T3, Jurkat and HL-1) as well as in primary cell culture from human skeletal muscle (myocytes and fibroblasts).In vivo, an ischemia-reperfusion model in dogs by coronary arterial occlusion was used (two hours of regional ischemia and three hours of reperfusion). In animals treated with halocin H6 there was a significant reduction of premature ventricular ectopic beats and infarct size, whereas blood pressure and heart rate remained unchanged. Up to date, halocin H6 is the only described biological molecule that exerts a, specific inhibitory activity in NHE of eukaryotic cells.[ES]: En el presente trabajo se evalúa la capacidad de la halocina H6 (una proteína tipo bacteriocina producida por la haloarchaea Haloferax gibbonsii) para inhibir el intercambiador Na+/H+ (NHE) de células de mamífero y su posible eficacia cardioprotectora frente a los daños causados por isquemia-reperfusión del miocardio. En experimentos in vitro H6 inhibe la actividad de NHE (determinada por citometría de flujo) de forma dosis-dependiente tanto en líneas celulares de mamíferos (HEK293, NIH3T3, Jurkat y HL-1) como en cultivos primarios de miocitos y fibroblastos aislados de músculo esquelético humano. En experimentos in vivo se utilizó un modelo de isquemia- reperfusión en perros por oclusión de la arteria coronaria (dos horas de isquemia y tres de reperfusión). En animales tratados con halocina H6 se produjo una disminución significativa a nivel estadístico, tanto del número de latidos ectópicos ventriculares como del tamaño del infarto, mientras que no se produjeron cambios tanto en la presión sanguínea como en el ritmo cardíaco. Hasta la fecha la halocina H6 es la única molécula biológica descrita que ejerce una actividad inhibidora específica sobre el NHE de células eucariotas.M. Dolz held a fellowship of CSIC-Bancaja Foundation. This work was supported in part by Spanish Council for Scientific Research (CSIC- 2001551).Peer reviewe