Post-transplant renal artery stenosis: The hemodynamic response to revascularization

Background. Percutaneous transluminal angioplasty and stenting are relatively noninvasive approaches to treat post-transplant renal artery stenosis. However, the real impact of this procedure on renal function recovery has never been quantitated precisely to date. Methods. In eight consecutive renal transplant patients with renal graft artery stenosis, blood pressure, body weight, and anatomical, functional, and Doppler ultrasound parameters were evaluated before and one month after renal artery transluminal angioplasty and stenting. On both occasions, glomerular filtration rate and renal plasma flow were evaluated by inulin and paraaminohippuric acid renal clearances, and glomerular size-selective function was evaluated by the fractional clearances of neutral dextran macromolecules. Results. The correction of renal artery stenosis, by normalizing renal vascular resistances, fully restored kidney perfusion and decreased arterial blood pressure, relieved water and sodium retention, restored an almost laminar arterial blood flow, and normalized vascular shear stress without appreciable effects on glomerular barrier size-selective function and proteinuria. Preangioplasty and postangioplasty renal resistive indices and peak systolic blood velocity estimated by Doppler ultrasounds were significantly correlated with the effective renal plasma flow and the blood velocity calculated at the site of stenosis. All patients were discharged without sequelae one or two days after angioplasty. Conclusions. Percutaneous transluminal angioplasty and stenting are safe and effective procedures to normalize the functional changes sustained by hemodynamically significant artery stenosis after renal transplantation. Doppler ultrasound scanning is a reliable and reproducible technique to monitor the renal functional response to vascular reperfusion

Modularità ed esperienza cosciente in una prospettiva neurocognitiva

Conscious experience seems to be an elusive matter of study for neuroscientific research. From an operational and neurocognitive point of view, however, conscious experience can be considered as a collection of events within a bidimensional framework. One dimension relates to wakefulness or the level of arousal, the other dimension relates to experiential contents, the objects of our phenomenal awareness. The variability of these two dimensions notwithstanding, the sense of conscious unity generally appears to be deep, real and immediate. Still, certain neurological conditions provide evidence for the hypothesis that this unity may be the result of a construction achieved by subtle and complex brain mechanisms. Taking the neurocognitive perspective, I will examine data coming from empirical research on patients with epilepsy and present some results from experiments conducted on split-brain patients and individuals in a minimally conscious state, which show how conscious experience may be rooted in the modular organisation of the brain

Pharmacological treatment of tics in Gilles de la Tourette Syndrome

Tourette syndrome is a neurodevelopmental disorder characterised by the chronic presence of multiple motor tics (e.g. eye blinking, shoulder shrugging, etc.) and at least one vocal/phonic tic (e.g. grunting or sniffing). The clinical picture of patients with Tourette syndrome is often complicated by tic-related behavioural problems and associated psychopathology. The pathophysiology of Tourette syndrome is poorly understood, however converging evidence from neuroimaging studies suggests abnormalities within the fronto-striatal pathways. The pharmacological management of the tic symptoms focuses on the dopaminergic and noradrenergic pathways and aims to improve the health-related quality of life of patients