Andrea Floris

Homozygosity for killer immunoglobin-like receptor haplotype A predicts complete molecular response to treatment with tyrosine kinase inhibitors in chronic myeloid leukemia patients.

Several recent reports suggest a possible role for killer immunoglobulin-like receptors (KIR) in the onset of chronic myeloid leukemia (CML) and response to therapy with tyrosine kinase inhibitors (TKIs). To explore this hypothesis, we studied KIRs and their human leukocyte antigen class I ligands in 59 consecutive patients with chronic-phase CML (mean age, 53 years; range, 23-81 years) and a group of 121 healthy control participants belonging to the same ethnic group as the patients. The 2-year cumulative incidence of complete molecular response, obtained after a median of 27 months (range, 4-52 months), was 51.2%. An increased frequency of the activating receptor KIR2DS1 (pm = 0.05) and a reduced frequency of the KIR-ligand combination KIR2DS2/2DL2 absent/C1 present (pm = 0.001) were significantly associated with CML. Moreover, KIR repertoires in patients appeared to influence response to TKI therapy. Homozygosity for KIR haplotype A (pm = 0.01), a decreased frequency of the inhibitory KIR gene KIR2DL2 (pm = 0.02), and low numbers of inhibitory KIR genes (pm = 0.05) were all significantly associated with achievement of complete molecular remission. These data suggest that a decrease in properly stimulated and activated NK cells might contribute to the occurrence of CML and indicate homozygosity for KIR haplotype A as a promising immunogenetic marker of complete molecular response that could help clinicians decide whether to withdraw treatment in patients with CML.

Reduced stress granule formation and cell death in fibroblasts with the A382T mutation of TARDBP gene: evidence for loss of TDP-43 nuclear function

TAR deoxyribonucleic acid-binding protein 43 (TDP-43) is a key protein in the pathogenesis of amyoptrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Recent studies suggest that mutations in the TDP-43 coding gene, TARDBP, as well as variations in TDP-43 protein expression levels may disrupt the dynamics of stress granules (SGs). However, it remains unclear whether the pathogenetic effect of the TDP-43 protein is exerted at the cytoplasmic level, through direct participation to SG composition, or at nuclear level, through control of proteins essential to SG assembly. To clarify this point, we investigated the dynamics of SG formation in primary skin fibroblast cultures from the patients with ALS together with the A382T mutation and the patients with ALS and healthy controls with wild-type TDP-43. Under stress conditions induced by sodium arsenite, we found that in human fibroblasts TDP-43 did not translocate to the SGs but instead contributed to the SG formation through a regulatory effect on the G3BP1 core protein. We found that the A382T mutation caused a significant reduction in the number of SGs per cell (P < 0.01) as well as the percentage of cells that form SGs (P < 0.00001). Following stress stimuli, a significant decrease of viability was observed for cells with the TDP-43 A382T mutation (P < 0.0005). We can therefore conclude that the A382T mutation caused a reduction in the ability of cells to respond to stress through loss of TDP-43 function in SG nucleation. The pathogenetic action revealed in our study model does not seem to be mediated by changes in the localization of the TDP-43 protein.

Absence of activating killer immunoglobulin-like receptor genes combined with hepatitis C viral genotype is predictive of hepatocellular carcinoma

Killer immunoglobulin-like receptors and their human leukocyte antigen class I ligands have a critical role in natural killer cell response to viral pathogens and tumors. To investigate whether killer immunoglobulin-like receptor genes could influence the chronic course of hepatitis C virus infection and/or progression to hepatocellular carcinoma we retrospectively analyzed a cohort of 228 patients transplanted for hepatitis C virus-induced cirrhotic end stage liver disease, combined or not with hepatocellular carcinoma. We found that patients completely lacking activating killer immunoglobulin-like receptor genes had a high risk of developing hepatocellular carcinoma. Hepatitis C viral genotype and viral load are other risk factors that can influence the course of chronic hepatitis C virus infection. In our study, the risk conferred by hepatitis C viral genotypes was enhanced in patients lacking activating killer immunoglobulin-like receptors. These results point to an important role for activating killer immunoglobulin-like receptors in the control of hepatitis C virus infection and progression to hepatocellular carcinoma. In clinical practice, assessment of killer immunoglobulin-like receptor and hepatitis C viral genotype combinations should allow for more accurate monitoring of patients with chronic hepatitis C virus infection.

Efficiency assessment of Electric Propulsion Systems for electric vehicles

An efficiency analysis of different configurations of Electric Propulsion Systems (EPSs) is presented in this paper. Particularly, three different Permanent Magnet Synchronous Machines (PMSMs) have been considered as the electric motor, which are characterized by different speed operating ranges and constant-power speed regions. In addition, four transmission systems are introduced and briefly described, i.e. Single-Gear, Multi-Gear, Continuously Variable and Magnetic Gear Transmission. Among these, the most suitable one is chosen for each PMSM in accordance with its inherent features. Subsequently, four EPSs have been designed based on specific vehicle traction and power requirements. The proposed EPS configurations are tested over three driving cycles in order to assess their efficiency over different driving conditions.

Design of a High-Speed ferrite-based Brushless DC Machine for electric vehicles

In this paper an analytical procedure for the preliminary design of a high-speed ferrite-based brushless dc machine (HS-BLDC) has been proposed. In particular, mechanical and electromagnetic modeling have been developed in order to take into account their mutual influence in the definition of the geometry of the electrical machine. In addition, suitable design targets have been imposed in accordance with electric vehicle application requirements. Hence, several mechanical and electromagnetic constraints have been introduced in order to comply with high-speed operation, preventing demagnetization issues of ferrite magnets as well. Subsequently, an HS-BLDC characterized by an inner rotor configuration has been designed in accordance with the proposed methodology. The analytical procedure and the corresponding results have been reported and validated by means of finite element analyses, highlighting the effectiveness of the proposed configuration and design solutions.

Design of a High-Speed Ferrite-based Brushless DC Machine for Electric Vehicles

In the present paper an analytic procedure for the preliminary design of a High-Speed ferrite-based Brushless DC Machine (HS-BLDC) has been proposed. In particular, a mechanical and electromagnetic modeling has been developed in order to take into account their mutual influence in the definition of the geometry of the electrical machine. In addition, suitable design targets have been imposed in accordance with electric vehicle application requirements. Hence, several mechanical and electromagnetic constraints have been introduced in order to comply with high-speed operation, preventing demagnetization issues of ferrite magnets as well. Subsequently, a HS-BLDC characterized by an inner rotor configuration has been designed in accordance with the proposed methodology. The analytical procedure and the corresponding results have been reported and validated by means of Finite Element Analyses (FEAs), highlighting the effectiveness of the proposed configuration and design solutions.

Modelling and design of PM retention sleeves for High-Speed PM Synchronous Machines

An analytical procedure for designing mechanical sleeves in surface-mounted High-Speed Permanent Magnet Synchronous Machines (HS-PMSMs) is presented in this paper. It is based on the theory of elastic mechanics and enables the computation of contact pressures between rotor layers (shaft, back-iron, permanent magnets and sleeve) and the Von Mises equivalent stress. The proposed procedure can be combined with the electromagnetic machine analysis, leading to fast and effective HS-PMSM design. This can be accomplished in accordance with different Permanent Magnets (PMs) and/or sleeve materials. Particularly, NdFeB and Ferrite-based PMs are alternatively considered, as well as the employment of Titanium and Carbon-Fiber as sleeve materials. The proposed approach is validated through Finite Element Analysis (FEA), which regards four different HS-PMSM configurations characterized by the same rated power and speed.

Modelling and real-time simulations of electric propulsion systems

This paper presents an advanced modelling of an Electric Propulsion System (EPS) for light-duty Electric Vehicles (EVs). It is developed within the Matlab Simulink environment by taking into account suitable models of each EPS components, namely the energy storage system, the electrical drive and the transmission system, as well as the overall vehicle model. Particularly, a Li-ion battery is considered, which supplies a Permanent Magnet Synchronous Machine (PMSM) through a two-level DC/AC converter. The latter is driven by a PI-based control system, which assures adequate PMSM performances at any speed within its operating speed range. Vehicle modelling is introduced as well, i.e. the PMSM is coupled to EV wheels through a single-gear transmission system. The proposed modelling approach is validated through both conventional and real-time simulations, the latter being carried out by interfacing Matlab Simulink with an OPAL-RT device.

Stress granules induced by oxidative stress in cultured fibroblast from TDP-43 mutant ALS patients

Stress granules (SGs) are transient cytoplasmic aggregates that rapidly form when cells are exposed to stress and consist of large messenger ribonucleoprotein (mRNPs) complexes. The SGs seem to function as storage depots for translation silenced complex and are implicated in stress-induced inhibition of global protein synthesis. Protein aggregation, has been observed in several neurodegenerative diseases, including Amyotrophic Lateral Sclerosis (ALS). The protein TDP-43 (TAR DNA-Binding Protein-43), encoded by one of the ALS-causative gene (TARDBP), is a major constituent of pathological inclusions in this disease and it is seems to be implicated in the regulation of SGs. Therefore we investigated the different characteristics of SGs in human cultured fibroblasts from ALS patients carrying TARDBPA382T mutation (group 1) versus healthy subjects (group 2). The cells were exposed to stressful conditions using sodium arsenite (SA) at different concentrations (0.5 mM, 1 mM) and exposure times (30 min, 1h). Preliminary results showed, after 30 minutes, small and sporadic cytoplasmic inclusions immunostained for TIA-1(T-cell internal antigen-1), an early marker for SGs, in both groups of cells. After 1h, the TIA-1 immunostained granules were bright, copious and scattered into the cytosol. Interestingly, we observed a significantly higher number of cells exhibiting SGs in fibroblasts from healthy controls (66%) compared to ALS patients (34%). In parallel, we identified the RNA binding protein HuR-1 (Human antigen R) in a fraction of Tia-1 positive SGs, as well as TDP- 43 localized into the nucleus of all the cells. These data raise the possibility that TDP-43 may modulate the stress granule formation, contributing to the cellular response to acute stress. Moreover the TDP-43 may regulate gene expression as well as cellular recovery and survival, and consequently its mutation may contribute to the neurodegeneration.