Effects of Impedance Reduction of a Robot for Wrist Rehabilitation on Human Motor Strategies in Healthy Subjects during Pointing Tasks

Studies on human motor control demonstrated the existence of simplifying strategies (namely `Donders' law') adopted to deal with kinematically redundant motor tasks. In recent research we showed that Donders' law also holds for human wrist during pointing tasks, and that it is heavily perturbed when interacting with a highly back-drivable state-of-the-art rehabilitation robot. We hypothesized that this depends on the excessive mechanical impedance of the Pronation/Supination (PS) joint of the robot and in this work we analyzed the effects of its reduction. To this end we deployed a basic force control scheme, which minimizes human-robot interaction force. This resulted in a 70% reduction of the inertia in PS joint and in decrease of 81% and 78% of the interaction torques during 1-DOF and 3-DOFs tasks. To assess the effects on human motor strategies, pointing tasks were performed by three subjects with a lightweight handheld device, interacting with the robot using its standard PD control (setting impedance to zero) and with the force-controlled robot. We quantified Donders' law as 2-dimensional surfaces in the 3-dimensional configuration space of rotations. Results revealed that the subject-specific features of Donders' surfaces reappeared after the reduction of robot impedance obtained via the force control

Time-course of plasma NT-proc-type natriuretic peptide in end-stage heart failure patients supported by left ventricular assist device implant

Purpose: Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) as well as the respective amino-terminal NT-proANP and NT-proBNP have now been well established as predictors of outcome in patients with heart failure (HF). C-type natriuretic peptide (CNP) and NT-proCNP are increased in HF patients as a function of disease severity, supporting a role for these peptides in the pathophysiology of HF, but their modifications during left ventricular assist device (LVAD) implant are lacking. Aim of this study was to evaluate the time-course of natriuretic peptides in end-stage HF patients undergoing LVAD implant in order to recognize new reliable predictive biomakers of cardiac recovery during LVAD. Methods: Five end-stage HF patients (NYHA class III and IV; age: 57?11 yrs; LVEF%<20) undergoing LVAD implantation were studied. Clinical hemodynamic evaluation and blood samples were obtained at admission (T1) and at 4, 24, 72 hrs and 1, 2, 4 weeks (T2-T7) after LVAD implant. NT-proANP and NT-proCNP were measured in plasma EDTA and aprotinin samples by a direct ELISA () while NT-proBNP by the Elecsys? 2010 analyzer. Results: The NT-proCNP time-course during LVAD was the following: T1=88.8?12.8 pg/ml; T2=144?29.8; T3=241.6?86.8 (p<0.05 vs T1); T4=229.7?66.4; T5=162.3?66.5; T6=175.3?47.7; T7=76.9?8 (p=ns vs T1). NT-proANP showed a similar pathway while NT-proBNP is reduced after LVAD implant (T1=4.1?2.2 ng/ml; T3=3.0?0.4), remaining lower than at baseline until 4 weeks (T7=3.1?0.9 ng/ml). NT-proCNP positively correlated with NT-proANP (p=0.03) while no correlation was found with NT-proBNP. Conclusions: This study reports for the first time original data on NT-proCNP levels after LVAD as a function of the time. The natriuretic peptides are differently modulated by LVAD, although all peptides resulted reduced after 4 weeks from implantation. The parallel determination of these effectors could allow us to obtain an integrated description of pathophysiological changes occurring during mechanical support

Relationship between Early Inflammatory Response and Clinical Evolution of the Severe Multiorgan Failure in Mechanical Circulatory Support-Treated Patients

Background. The mechanical circulatory support (MCS) is an effective treatment in critically ill patients with end-stage heart failure (ESHF) that, however, may cause a severe multiorgan failure syndrome (MOFS) in these subjects. The impact of altered inflammatory response, associated to MOFS, on clinical evolution of MCS postimplantation patients has not been yet clarified. Methods. Circulating cytokines, adhesion molecules, and a marker of monocyte activation (neopterin) were determined in 53MCStreated patients, at preimplant and until 2 weeks. MOFS was evaluated by total sequential organ failure assessment score (tSOFA). Results. During MCS treatment, 32 patients experienced moderate MOFS (tSOFA< 11; A group), while 21 patients experienced severe MOFS (tSOFA? 11) with favorable (B group) or adverse (&#55349;&#56411; = 13, C group) outcomes. At preimplant, higher values of left ventricular ejection fraction (LVEF) and estimated glomerular filtration rate (eGFR) were the only parameter independently associated with A group. In C group, during the first postoperative week, high levels of interleukin-8 (IL-8) and tumor necrosis factor (TNF)-&#55349;&#57084;, and an increase of neopterin and adhesionmolecules, precede tSOFA worsening and exitus. Conclusions.TheMCS patients of C group show an excessive release to IL-8 and TNF-&#55349;&#57084;, and monocyte-endothelial activation after surgery, that might contribute to the unfavourable evolution of severe MOFS

Ketogenic diet: a tool for the management of neuroendocrine neoplasms?

Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplasms, whose incidence has rapidly increased in the last years. Nutrition plays an important role in their management; indeed, malnutrition negatively impacts on rates of complications, hospitalization, hospital stay, costs and mortality. Furthermore, it has been reported that a poor nutritional status could influence the outcome of patients with pancreatic NENs. Moreover, obesity, predisposing to insulin resistance and compensatory hyperinsulinemia, could stimulate the growth of these neoplasms. Ketogenic diet (KD), a high-fat, low-carbohydrate diet with adequate amounts of protein, has been reported to be a promising approach for the management of several types of cancer, mostly gynecological and neurological ones. Indeed, it appears to sensitize most cancers to standard treatment by exploiting the reprogramed metabolism of cancer cells and thus resulting in a promising candidate as an adjuvant cancer therapy. Thus, the aim of this review is to provide an overview on the importance of nutrition in cancer management and in particular in NENs' setting. Furthermore, we reported the current evidence on the efficacy of KD in the management of cancer and based on molecular mechanisms; we also hypothesize the potential use of this nutritional pattern in the management of NENs

Reduced myocardial MMP-2, MMP-9 and gluatione peroxidase activities and elevated cytokine levesl in patients supported by left ventricular assist device

To asssess the effects of LVAD implant in end-stage heart failure patients on the extracellular matrix oxidative stress and inflammatory sat

Relationship between Early Inflammatory Response and Clinical Evolution of the Severe Multiorgan Failure in Mechanical Circulatory Support-Treated Patients

Background. The mechanical circulatory support (MCS) is an effective treatment in critically ill patients with end-stage heart failure (ESHF) that, however, may cause a severe multiorgan failure syndrome (MOFS) in these subjects. The impact of altered inflammatory response, associated to MOFS, on clinical evolution of MCS postimplantation patients has not been yet clarified. Methods. Circulating cytokines, adhesion molecules, and a marker of monocyte activation (neopterin) were determined in 53 MCS-treated patients, at preimplant and until 2 weeks. MOFS was evaluated by total sequential organ failure assessment score (tSOFA). Results. During MCS treatment, 32 patients experienced moderate MOFS (tSOFA < 11; A group), while 21 patients experienced severe MOFS (tSOFA ≥ 11) with favorable (B group) or adverse (n=13, C group) outcomes. At preimplant, higher values of left ventricular ejection fraction (LVEF) and estimated glomerular filtration rate (eGFR) were the only parameter independently associated with A group. In C group, during the first postoperative week, high levels of interleukin-8 (IL-8) and tumor necrosis factor (TNF)-α, and an increase of neopterin and adhesion molecules, precede tSOFA worsening and exitus. Conclusions. The MCS patients of C group show an excessive release to IL-8 and TNF-α, and monocyte-endothelial activation after surgery, that might contribute to the unfavourable evolution of severe MOFS

Myocardial redox state alterations and elevated cytokines levels in patients with end stage heart failure (ESHF) supported by left ventricular assist device (LVAD)

To assess the effects of mechanical unloading by LVAD on the interplay between redox pathways and inflammatory status in ESHF

Early Expression of Pro- and Anti-Inflammatory Cytokines in Left Ventricular Assist Device Recipients With Multiple Organ Failure Syndrome

To assess whether the combined evaluation of total Sequential Organ Failure Assessment (t-SOFA) score and pro- and anti-inflammatory cytokine profiles early after left ventricular assist device (LVAD) implant discriminates patients at high risk for multiple organ failure syndrome (MOFS) in the first month post-LVA