Accuracy of flow volume estimation in the dilated aorta using 4D flow MRI: a pulsatile phantom study

Autores: Eduardo E Rodríguez, Alejandro Valda, Mariano E Casciaro, Sebastian Graf, Edmundo Cabrera Fischer, Damian Craiem

Aortic dilatation is a severe pathology that increases the risk of rupture and its hemodynamics could be accurately assessed by using the 4D flow cardiovascular magnetic resonance (CMR) technique but flow assessment under complex flow patterns require validation. The aim of this work was to develop anin vitrosystem compatible with CMR to assess the accuracy of volume flow measurements in dilated aortas.Approach.Two latex models, one with ascending and the other with abdominal aortic aneurysms were manufactured to ensure a constant and controlled net flow volume along the aortic length. A pneumatic piston driven by a stepper motor and controlled by an embedded system located in the control room modulated a pulsatile fluid flow using a pump with an elastic membrane placed in the magnet near the elastic models. All the visualization and measurement algorithms were integrated into a custom computer platform. 4D flow imaging was used to estimate the flow rate and volume through multiple aortic planes and compared to the reference assessed by weight method and to 2D flow measurements.Main results.The errors of flow volume assessment using 4D flow remained within reasonable limits along the length of the aortic models. Mean differences in net flow volume from the reference were less than 2 ml (range -4 to 6 ml), corresponding to mean relative differences of less than 4% (range -8% to 11%). Averaged net, forward and backward flow volume estimations along the aortic length were similar using 2D and 4D flow measurements (p> 0.05). Peak forward and backward flow rates increased in the dilated regions and were comparable to those observed in patients.Significance.The accuracy of flow volume estimates in complex flow patterns, such as those observed in patients with aneurysms, was validatedin vitrousing 4D flow.

Disponible en: PubMed

Low regulatory T-cells frequency is associated with graft rejection after small bowel transplantation: Clinical and experimental evidence

Autores: Rodrigo Papa-GobbiID, Pablo Stringa, Maria Virginia Gentilini , Ivana Ivanoff , Mariana Machuca, Nidia Monserrat Arreola, Javier Serradilla, Karla EstefaníaFernández, Paloma Talayero, María Velayos, Elena Sánchez—Zapardiel , Gabriel Gondolesi , Ane Andrés-Moreno, Martin Rumbo, Francisco HernándezOliveros

Intestinal transplantation (ITx) represents the only curative option for patients with irreversible intestinal failure. Nevertheless, its rejection rate surpasses that of other solid organ transplants due to the heightened immunological load of the gut. Regulatory T-cells (Tregs) are key players in the induction and maintenance of peripheral tolerance, suggesting their potential involvement in modulating host vs. graft responses after ITx. Thus, we investigated the association of Tregs with allograft outcomes in pediatric patients and in an experimental model of small bowel transplantation.

Disponible en: Plos One

Role of glucocorticoid receptor expression in Chronic Chagas Cardiomyopathy: implications for inflammation and cardiac hypertrophy

Autores:  Florencia B. González • Antonella Pacini • Araceli Castro • Susana Lioi • Silvina R. Villar • Luciano D’Attilio • Rodolfo D. Leiva • Liliana Favaloro • Oscar A. Bottasso • Carlos A. Vigliano • Ana Rosa Pérez

Resumen: Chronic Chagasic Cardiomyopathy (CCC) has an infectious and inflammatory nature. Recent data also suggest an association with altered regulation of glucocorticoid (GC)-mediated circuits failing to control systemic inflammation. However, the involvement of glucocorticoid receptors (GR) and their isoforms have been unexplored.

Disponible en: Frontiers