17 research outputs found
Direct alloreactivity is more susceptible to regulation by natural regulatory T cells than indirect alloreactivity.
No full textInternational audienceThe contribution of natural CD4(+)CD25(+) regulatory T cells (nTregs) in controlling graft rejection and the mechanism used remain controversial. Using the duality of the 2.102 TCR Ag recognition, we were able to study, for the first time to our knowledge, the involvement of nTregs in the two pathways of allorecognition in a murine adoptive transfer model in which TCR-transgenic nTregs were or were not depleted before transplantation. We show that nTregs used at a physiological ratio were able to delay graft rejection after direct alloreactivity by controlling proliferation and differentiation of alloreactive CD4(+) conventional T cells in draining lymph nodes. In contrast, similar results were found in the indirect alloreactivity pathway only when nTregs were used in high numbers. In the latter pathway, nTregs used at a physiological ratio failed to delay graft rejection and to control proliferation of conventional T cells. These results support recent therapeutic approaches aimed at producing and using in vitro Ag-specific Foxp3(+) nTregs to control graft rejection in transplantation. Finally, late inhibition of Th1 differentiation was shown in indirect alloreactivity, but this suppression could also be mediated by Foxp3(+)-induced Tregs
Wireless Body Area Networks: Applications and Technologies
No full textAbstractThe increasing use of wireless networks and the constant miniaturization of electrical invasive/non-invasive devices have empow- ered the development of Wireless Body Area Networks (WBANs). A WBAN provides a continuous health monitoring of a patient without any constraint on his/her normal daily life activities. Many technologies have proved their efficiency in supporting WBANs applications, such as remote monitoring, biofeedback and assisted living by responding to their specific quality of service (QoS) requirements. Due to numerous available technologies, selecting the appropriate technology for a medical application is being a challenging task. In this paper, the different medical applications are presented. The most common technologies used in WBANs are highlighted. Finally, a matching between each application and the corresponding suitable technology is studied
Cerebrospinal fluid IL-10 as an early stage discriminative marker between multiple sclerosis and neuro-Behçet disease.
No full textInternational audienceMultiple Sclerosis (MS) and Neuro-Behçet's Disease (NBD) are two recurrent disorders affecting the central nervous system (CNS) by causing inflammation and irreversible damage. Inaugural clinical symptoms for both diseases might be very similar and definitive diagnosis could be delayed. The present study aimed to find out possible differences at early stages in the transcription factors/cytokines expression profiles in blood and cerebrospinal fluid (CSF) of MS and NBD patients which could be useful discriminative markers. Cytokines and transcription factors related to Th1, Th2, Th17 and T regulatory populations were studied by quantitative RT-PCR simultaneously in PBMCs and CSF, from 40 patients presenting a first episode of clinical features related to CNS inflammation and 22 controls with non inflammatory neurological diseases enrolled mainly for severe headache. The follow up of 12 months did allow a definitive diagnosis of remitting relapsing MS (RRMS) in 21 patients and of NBD in the other 19 among those with CNS inflammation compared to controls. In initial blood samples, T-bet was significantly increased in NBD patients only while IFN-γ was elevated in patients who evolved into RRMS or NBD. IL-17a, GATA-3 and IL-4 were significantly lower in RRMS patients than in the NBD group. In initial CSF samples, ROR-γt, IL-17a and IFN-γ were significantly elevated in patients compared to controls. The most striking finding was the significant increase of CSF IL-10 that we did observe in NBD patients only. Thus, we propose CSF IL-10 as a predictive marker to help clinicians discriminating between these two neurological disorders
Autonomous Approach and Landing Algorithms for Unmanned Aerial Vehicles
No full textIn recent years, several research activities have been developed in order to increase the autonomy features in Unmanned Aerial Vehicles (UAVs), to substitute human pilots in dangerous missions or simply in order to execute specific tasks more efficiently and cheaply. In particular, a significant research effort has been devoted to achieve high automation in the landing phase, so as to allow the landing of an aircraft without human intervention, also in presence of severe environmental disturbances. The worldwide research community agrees with the opportunity of the dual use of UAVs (for both military and civil purposes), for this reason it is very important to make the UAVs and their autolanding systems compliant with the actual and future rules and with the procedures regarding autonomous flight in ATM (Air Traffic Management) airspace in addition to the typical military aims of minimizing fuel, space or other important parameters during each autonomous task.
Developing autolanding systems with a desired level of reliability, accuracy and safety involves an evolution of all the subsystems related to the guide, navigation and control disciplines. The main drawbacks of the autolanding systems available at the state of art concern or the lack of adaptivity of the trajectory generation and tracking to unpredicted external events, such as varied environmental condition and unexpected threats to avoid, or the missed compliance with the guide lines imposed by certification authorities of the proposed technologies used to get the desired above mentioned adaptivity.
During his PhD period the author contributed to the development of an autonomous approach and landing system considering all the indispensable functionalities like: mission automation logic, runway data managing, sensor fusion for optimal estimation of vehicle state, trajectory generation and tracking considering optimality criteria, health management algorithms.
In particular the system addressed in this thesis is capable to perform a fully adaptive autonomous landing starting from any point of the three dimensional space. The main novel feature of this algorithm is that it generates on line, with a desired updating rate or at a specified event, the nominal trajectory for the aircraft, based on the actual state of the vehicle and on the desired state at touch down point. Main features of the autolanding system based on the implementation of the proposed algorithm are: on line trajectory re-planning in the landing phase, fully autonomy from remote pilot inputs, weakly instrumented landing runway (without ILS availability), ability to land starting from any point in the space and autonomous management of failures and/or adverse atmospheric conditions, decision-making logic evaluation for key-decisions regarding possible execution of altitude recovery manoeuvre based on the Differential GPS integrity signal and compatible with the functionalities made available by the future GNSS system.
All the algorithms developed allow reducing computational tractability of trajectory generation and tracking problems so as to be suitable for real time implementation and to still obtain a feasible (for the vehicle) robust and adaptive trajectory for the UAV.
All the activities related to the current study have been conducted at CIRA (Italian Aerospace Research Center) in the framework of the aeronautical TECVOL project whose aim is to develop innovative technologies for the autonomous flight. The autolanding system was developed by the TECVOL team and the author’s contribution to it will be outlined in the thesis.
Effectiveness of proposed algorithms has been then evaluated in real flight experiments, using the aeronautical flying demonstrator available at CIRA
B Cells Specific CpG Induces High IL-10 and IL-6 Expression In Vitro in Neuro-Behçet’s Disease
No full textRemitting-RelapsingMultiple Sclerosis (RRMS) and Neuro-Behçet Disease (NBD) are two chronic neuroinflammatory disorders leading to neurological damage. Herein, we investigated in these patients the IL-10-producing cells during the early stages of these disorders. Cellular and molecular investigations were carried out on treatment naive patients suffering from RRMS and NBD recruited at the first episode of clinical relapse. Our findings demonstrate that CSF-B cells from NBD patients, but not RRMS, are the major source of intrathecal IL-10 as compared to T-CD4 cells. Moreover, we showed a lower expression of TGF-β and IL35, in the CSF cells of NBD patients as compared to the control group. Specific in vitro CpG stimulation of peripheral blood B cells from NBD patients resulted in a concomitant early mRNA expression of IL6 and IL10 but was limited to IL10 for RRMS patients. Furthermore, mRNA expression of IL-6 and IL-10 receptors was assessed and intriguingly IL6ST receptor subunit was significantly lower in NBD CSF, but not RRMS while IL10RB was increased in both. Deciphering the role of increased IL-10-producing B cells and IL10RB despite relapsing disease as well as the discordant expression of IL6 and IL6ST may pave the way for a better understanding of the pathophysiology of these neuro-inflammatory disorders
Increased T-bet/GATA-3 and ROR-γt /Foxp3 Ratios in Cerebrospinal Fluid as Potential Criteria for Definite Neuro-Behçet’s Disease
No full textWhen the central nervous system (CNS) is the primary affected site in an initial attack of Behçet’s disease (BD), the differential diagnosis is particularly challenging. Some cases remain unclassified or qualified as probable neuro-Behçet’s disease (NBD). Several cytokines are involved in the immunopathogenesis of this disease; however, studies establishing the differential cytokine pattern between probable and definite NBD are scarce. Twenty-eight parenchymal NBD patients, diagnosed according to the International Consensus Recommendation (ICR) criteria and classified into definite (D-NBD; n = 17) and probable (P-NBD; n = 11), were sampled at their first neurological symptoms, and compared with healthy control subjects (n = 20). Oligoclonal bands (OCB) of IgG were detected by isoelectric focusing on agarose, and immunoblotting of matched serum and cerebrospinal fluid (CSF) sample pairs. T cell cytokines (INF-γ, IL-4, IL-17, and IL-10) and transcription factors related to Th1, Th2, Th17, and T regulatory populations (respectively T-bet, GATA-3, ROR-γt, and Foxp3) were studied by quantitative RT-PCR in peripheral blood mononuclear cells (PBMCs) and CSF cells. Inflammatory cytokines such as IL-6, TNF-α, and IL-1β were also analyzed. CSF OCB pattern 2 was present in only 1 out of 28 neuro-Behçet’s patients who belonged to the P-NBD group. Two D-NBD patients had OCB in CSF showing pattern 4. In the D-NBD CSF samples, IL-17 and IL-10 expressions were significantly elevated compared to P-NBD. Moreover, D-NBD patients had increased levels of T-bet/GATA-3 and ROR-γt/Foxp3 ratios compared to P-NBD. Furthermore, a significant increase of CSF IL-6 in D-NBD, compared to P-NBD and the controls, was found. In addition to the increased IL-6 level, the data obtained suggest the existence in D-NBD patients of a significantly disrupted balance between Th17 effector and T regulatory cells, as reflected by the enhanced ROR-γt/Foxp3 ratio. This could be considered as an additional criterion for definite neuro-Behçet’s disease
Electrostatic spray ionization from 384-well microtiter plates for mass spectrometry analysis based enzyme assay and drug metabolism screening
No full textWe have realized the direct ionization of samples from wells of microtiter plates under atmospheric conditions for mass spectrometry analysis without any liquid delivery system or any additional interface. The microtiter plate is a commercially available 384-well plate without any modification, working as a container and an emitter for electrostatic spray ionization of analytes. The approach provides high throughput for the large batches of reactions and both the qualitative and quantitative analysis of a single compound or mixture. The limits of detection in small drug molecules, peptides and proteins are similar in comparison with standard direct infusion electrospray ionization. The analysis time per well is only seconds. These analytical merits benefit many microtiter plate-based studies such as combinatorial chemistry and high throughput screening in enzyme assay or drug metabolism. Herein, we illustrate the application in enzyme assay using tyrosine oxidation catalyzed by tyrosinase in the presence or absence of inhibitors. The potential application in drug development is also demonstrated with cytochrome P450-catalyzed metabolic reactions of two drugs in microtiter plates followed with direct ESTASI-MS/MS based characterization of the metabolism products.LEP
Image_2_Longitudinal and Comparative Analysis of Gut Microbiota of Tunisian Newborns According to Delivery Mode.jpeg
No full textMicrobiota colonization is a dynamic process that impacts the health status during an individual's lifetime. The composition of the gut microbiota of newborns is conditioned by multiple factors, including the delivery mode (DM). Nonetheless, the DM's influence remains uncertain and is still the subject of debate. In this context, the medical indication and the emergency of a cesarean delivery might have led to confounding conclusions regarding the composition and diversity of the neonatal microbiome. Herein, we used high-resolution shotgun sequencing to decipher the composition and dynamics of the gut microbiota composition of Tunisian newborns. Stool samples were collected from 5 elective cesarean section (ECS) and 5 vaginally delivered (VD) newborns at the following time points: Day 0, Day 15, and Day 30. The ECS and VD newborns showed the same level of bacterial richness and diversity. In addition, our data pointed to a shift in microbiota community composition during the first 2 weeks, regardless of the DM. Both ECS and VD showed a profile dominated by Proteobacteria, Actinobacteria, and Firmicutes. However, ECS showed an underrepresentation of Bacteroides and an enrichment of opportunistic pathogenic species of the ESKAPE group, starting from the second week. Besides revealing the intestinal microbiota of Tunisian newborns, this study provides novel insights into the microbiota perturbations caused by ECS.</p
Table_3_Longitudinal and Comparative Analysis of Gut Microbiota of Tunisian Newborns According to Delivery Mode.xlsx
No full textMicrobiota colonization is a dynamic process that impacts the health status during an individual's lifetime. The composition of the gut microbiota of newborns is conditioned by multiple factors, including the delivery mode (DM). Nonetheless, the DM's influence remains uncertain and is still the subject of debate. In this context, the medical indication and the emergency of a cesarean delivery might have led to confounding conclusions regarding the composition and diversity of the neonatal microbiome. Herein, we used high-resolution shotgun sequencing to decipher the composition and dynamics of the gut microbiota composition of Tunisian newborns. Stool samples were collected from 5 elective cesarean section (ECS) and 5 vaginally delivered (VD) newborns at the following time points: Day 0, Day 15, and Day 30. The ECS and VD newborns showed the same level of bacterial richness and diversity. In addition, our data pointed to a shift in microbiota community composition during the first 2 weeks, regardless of the DM. Both ECS and VD showed a profile dominated by Proteobacteria, Actinobacteria, and Firmicutes. However, ECS showed an underrepresentation of Bacteroides and an enrichment of opportunistic pathogenic species of the ESKAPE group, starting from the second week. Besides revealing the intestinal microbiota of Tunisian newborns, this study provides novel insights into the microbiota perturbations caused by ECS.</p
Table_1_Longitudinal and Comparative Analysis of Gut Microbiota of Tunisian Newborns According to Delivery Mode.XLSX
No full textMicrobiota colonization is a dynamic process that impacts the health status during an individual's lifetime. The composition of the gut microbiota of newborns is conditioned by multiple factors, including the delivery mode (DM). Nonetheless, the DM's influence remains uncertain and is still the subject of debate. In this context, the medical indication and the emergency of a cesarean delivery might have led to confounding conclusions regarding the composition and diversity of the neonatal microbiome. Herein, we used high-resolution shotgun sequencing to decipher the composition and dynamics of the gut microbiota composition of Tunisian newborns. Stool samples were collected from 5 elective cesarean section (ECS) and 5 vaginally delivered (VD) newborns at the following time points: Day 0, Day 15, and Day 30. The ECS and VD newborns showed the same level of bacterial richness and diversity. In addition, our data pointed to a shift in microbiota community composition during the first 2 weeks, regardless of the DM. Both ECS and VD showed a profile dominated by Proteobacteria, Actinobacteria, and Firmicutes. However, ECS showed an underrepresentation of Bacteroides and an enrichment of opportunistic pathogenic species of the ESKAPE group, starting from the second week. Besides revealing the intestinal microbiota of Tunisian newborns, this study provides novel insights into the microbiota perturbations caused by ECS.</p
