Formyl Peptide Receptor 1 Modulates Endothelial Cell Functions by NADPH Oxidase-Dependent VEGFR2 Transactivation

In the vasculature, NADPH oxidase is the main contributor of reactive oxygen species (ROS) which play a key role in endothelial signalling and functions. We demonstrate that ECV304 cells express p47phox, p67phox, and p22phox subunits of NADPH oxidase, as well as formyl peptide receptors 1 and 3 (FPR1/3), which are members of the GPCR family. By RT-PCR, we also detected Flt-1 and Flk-1/KDR in these cells. Stimulation of FPR1 by N-fMLP induces p47phox phosphorylation, which is the crucial event for NADPH oxidase-dependent superoxide production. Transphosphorylation of RTKs by GPCRs is a biological mechanism through which the information exchange is amplified throughout the cell. ROS act as signalling intermediates in the transactivation mechanism. We show that N-fMLP stimulation induces the phosphorylation of cytosolic Y951, Y996, and Y1175 residues of VEGFR2, which constitute the anchoring sites for signalling molecules. These, in turn, activate PI3K/Akt and PLC-γ1/PKC intracellular pathways. FPR1-induced ROS production plays a critical role in this cross-talk mechanism. In fact, inhibition of FPR1 and/or NADPH oxidase functions prevents VEGFR2 transactivation and the triggering of the downstream signalling cascades. N-fMLP stimulation also ameliorates cellular migration and capillary-like network formation ability of ECV304 cells

Role of polymer network and gelation kinetics on the mechanical properties and adsorption capacity of chitosan hydrogels for dye removal

Chitosan (CS) hydrogels are receiving growing attention as adsorbents for water purification purposes. The conditions of preparation of this class of materials play a crucial in the determination of their performances; however, this aspect is often neglected in the literature. In this study, we deal with this issue, focusing on the structure-property relationships of CS hydrogels obtained by phase inversion method. We show that the concentration of the starting solution determines the density and strength of intermolecular interactions, and that the gelation kinetics dictates the hydrogel structure at the microscale. Consequently, even subtle changes in the preparation protocol can cause significant differences in the performances of CS hydrogels in terms of mechanical properties and dye adsorption capacity. The observed trends are often neither trivial nor monotonic. Nonetheless, we demonstrate that they can be interpreted looking at the CS network structure, which can be inferred by rheological measurements

Sustainable and Green Production of Nanostructured Cellulose by a 2-Step Mechano-Enzymatic Process

Nanostructured cellulose (NC) represents an emerging sustainable biomaterial for diverse biotechnological applications; however, its production requires hazardous chemicals that render the process ecologically unfriendly. Using commercial plant-derived cellulose, an innovative strategy for NC production based on the combination of mechanical and enzymatic approaches was proposed as a sustainable alternative to conventional chemical procedures. After ball milling, the average length of the fibers was reduced by one order of magnitude (down to 10–20 μm) and the crystallinity index decreased from 0.54 to 0.07–0.18. Moreover, a 60 min ball milling pre-treatment followed by 3 h Cellic Ctec2 enzymatic hydrolysis led to NC production (15% yield). Analysis of the structural features of NC obtained by the mechano-enzymatic process revealed that the diameters of the obtained cellulose fibrils and particles were in the range of 200–500 nm and approximately 50 nm, respectively. Interestingly, the film-forming property on polyethylene (coating ≅ 2 μm thickness) was successfully demonstrated and a significant reduction (18%) of the oxygen transmission rate was obtained. Altogether, these findings demonstrated that nanostructured cellulose could be successfully produced using a novel, cheap, and rapid 2-step physico-enzymatic process that provides a potential green and sustainable route that could be exploitable in future biorefineries

A self-attention deep neural network regressor for real time blood glucose estimation in paediatric population using physiological signals

With the advent of modern digital technology, the physiological signals (such as electrocardiogram) are being acquired from portable wearable devices which are being used for non-invasive chronic disease management (such as Type 1 Diabetes). The diabetes management requires real-time assessment of blood glucose which is cumbersome for paediatric population due to clinical complexity and invasiveness. Therefore, real-time non-invasive blood glucose estimation is now pivotal for effective diabetes management. In this paper, we propose a Self-Attention Deep Neural Network Regressor for real-time non-invasive blood glucose estimation for paediatric population based on automatically extracted beat morphology. The first stage performs Morphological Extractor based on Self-Attention based Long Short-Term Memory driven by Convolutional Neural Network for highlighting local features based on temporal context. The second stage is based on Morphological Regressor driven by multilayer perceptron with dropout and batch normalization to avoid overfitting. We performed feature selection via logit model followed by Spearman’s correlation among features to avoid feature redundancy. We trained as tested our model on publicly available MIT/BIH-Physionet databases and physiological signals acquired from a T1D paediatric population

Focolaio di COVID-19 in un campo estivo nella Regione Piemonte (2021): descrizione, lezioni apprese e raccomandazioni per futuri campi estivi

COVID-19 outbreak at a summer camp in Piedimont region in 2021: description, lessons learned and recommendations for future summer camps Introduction In August 2021, an outbreak of coronavirus disease 2019 (COVID-19) occurred in a summer camp in Piedmont region, Italy, affecting primarily campers aged ≤16 years. We conducted a retrospective cohort study among campers and personnel (attendees) to determine the attack rate (AR), evaluate possible factors associated with transmission and propose recommended measures for the organization of future summer camps. Materials and methods A de-identified database including demographic, role of attendees, cohorting, means of transportation to the camp, inter-camper interactions, SARS-CoV-2 testing results and symptomatology was used. All analysis data came from a collection of data carried out by the organizing private company and the information related to the mitigation protocol put in place was provided by the health care personnel. All campers were asked to have an antigen/molecular test within 72 hours before departure. Nine dedicated buses departed from different Italian regions towards the camp. All travellers wore a surgical mask during the trip. Upon arrival, regardless of the bus used, the campers were divided into 11 subgroups with no further contact between them unless they were blood relatives. No SARS-CoV-2 screening tests were scheduled for campers after arrival and during the camp period. On the other hand, personnel had a screening test at each shift change. During the camp period, antigen tests were performed at cases with symptoms suggestive of infection. Only attendees enrolled in the private company and those who received at least one test since arrival at the camp were considered in the study. We calculated overall AR and relative risk (RR) along with specific, transmission-focused risk factors. Results Among the 187 study participants, the median age was 14 years (range: 6-45). Seven days after arrival at the camp, 8 campers developed symptoms and tested positive. The overall AR was 33.7% (63 out of 187), and 34.2% (50/146) for campers and 31.7% (13/41) for staff, respectively. Among those with available symptoms information, 72% (36/50) were asymptomatic at the time of testing. Only 17.1% of campers had direct contact with blood relatives from other subgroups. The AR of participants using a bus was 36.2% (59/163) with an RR of 1.18 (95% CI = 0.51-2.73,) and the AR of those belonging to a subgroup was 35% (62/177) with an RR of 3.5 (95% CI = 0.54-22.7). For personnel, participation to a subgroup gave an AR of 38.7% (12/31) and an RR of 3.87 (95% CI = 0.57-26.18). All but four subgroups had a high AR (>33,3). Conclusions Getting tested prior to traveling and campers separation into low-contact subgroups was not sufficient enough to avoid a high number of infections in this summer camp. Analysis did not allow the identification of an index case or helped to understand whether the outbreak originated from the attendees who travelled on the same bus. The high AR observed in all subgroups suggest that there was frequent contact between attendees belonging to different subgroups. Sharing of common areas such as the canteen and contact between attendees are possible factors that have contributed to the spread of the outbreak. The experience gained by the analysis of this data was used for the review of measures for the organization of summer camps in 2022

Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago

Background: Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA. Methods: This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up. Results: 564 patients (43.1%) were females. The mean age was 65.9 ± 15.6 years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P < 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections. Conclusions: After 100 years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Intracellular signaling cascades activated by Formyl Peptide Receptors

The formyl peptide receptors FPR1, FPR2 and FPR3 are seven transmembrane Gi-protein coupled receptors. They were first identified as mediators of chemotaxis and activation of leukocytes in response to bacterial formylated peptides. To date, expression of FPRs was described also in non-myeloid cells, together with the ability of these receptors to recognize an heterogenous range of ligands of different origin. In the last few years, FPRs activation or their overexpression has been correlated to cell tumorigenicity, inflammation, cell proliferation, invasion and tumour progression. Furthermore, increasing evidence have highlighted the ability of FPRs to transactivate receptor tyrosine kinase (RTKs) through NADPH oxidase-dependent production of reactive oxygen species (ROS). Herein, we investigated (i) the ability of FPR1 to transactivate the nerve growth factor receptor TrkA, in SH-SY5Y human neuroblastoma cell line; (ii) the involvement of NADPH oxidase-derived ROS in mediating TrkA transactivation; (iii) the downstream signaling cascades triggered by FPR1 stimulation and, in turn, by TrkA transactivation; (iv) the biological effects of FPR1 activation. Western blotting experiments demonstrated that FPR1 stimulation mediates NADPH oxidase-dependent phosphorylation of cytosolic residues Y490, Y751, and Y785 of TrkA, that represent docking sites for Erk, Akt and PKC pathway activation. Cell count assay, neurite outgrowth assay and wound-healing assay indicated that FPR1-mediated TrkA phosphorylation enhances cell proliferation, growth and migration. Furthermore, to characterize phosphorylations of intracellular signaling molecules triggered by FPR activation, we performed a TiO2-based affinity chromatography to obtain an enrichment of phosphoproteins derived from FPR2 stimulation. Mass spectrometry analysis identified 290 differentially phosphorylated proteins and 53 unique phosphopeptides. Phosphorylations of five selected phosphoproteins (HSP-27, MCM2, OSR1, Rb and MARCKS) were further validated by western blotting experiments, confirming their dependence on FPR2 activation. Furthermore, we show that FPR2 stimulation with two anti-inflammatory agonists (Annexin A1 or Lipoxin A4) induces the phosphorylation of selected differentially phosphorylated proteins, suggesting their role in the resolution of inflammation. Taken together, these data represent a promising resource for further studies on new signaling networks established by FPRs that could lead to the identification of novel molecular drug targets for human diseases

Vibration Response Aspects of a Main Landing Gear Composite Door Designed for High-Speed Rotorcraft

One of the crucial issues affecting the structural safety of propeller vehicles is the propeller tonal excitation and related vibrations. Propeller rotation during flight generates vibrating sources depending upon its rotational angular velocity, number of blades, power at shaft generating aircraft thrust, and blade geometry. Generally, the higher energy levels generated are confined to 1st blade passing frequency (BPF) and its harmonics, while additional broadband components, mainly linked with the blade shape, the developed engine power, and the turbulent boundary layer (TBL), also contribute to the excitation levels. The vibrations problem takes on particular relevance in the case of composite structures. The laminates in fact could exert damping levels generally lower than metallic structures, where the greater amount of bolted joints allow for dissipating more vibration energy. The prediction and reduction of aircraft vibration levels are therefore significant considerations for conventional propeller aircrafts now entering the commercial market as well as for models currently being developed. In the Clean Sky 2 framework, the present study focuses on a practical case inherent to the AIRBUS-Racer program aiming to design and develop a multi-tasking fast rotorcraft. This paper defines a finite elements (FE)-based procedure for the characterization of the vibration levels of a main landing gear (MLG) composite door with respect to the expected operating tonal loads. A parametric assessment was carried out to evaluate the principal modal parameters (transfer functions and respective resonance frequencies, mode shapes, and damping coefficients) of the landing gear-door assembly in order to achieve reduced vibration levels. Based on the FE analysis results, the influence of the extra-damping, location, and number of ballast elements, the boundary conditions were investigated with respect to failure scenarios of the kinematic line opening the study towards aeroelastic evaluations. Further experimental ground test results serve as a validation database for the prediction numerical methods representative of the composite door dynamic response

Vibration Response Aspects of a Main Landing Gear Composite Door Designed for High-Speed Rotorcraft

One of the crucial issues affecting the structural safety of propeller vehicles is the propeller tonal excitation and related vibrations. Propeller rotation during flight generates vibrating sources depending upon its rotational angular velocity, number of blades, power at shaft generating aircraft thrust, and blade geometry. Generally, the higher energy levels generated are confined to 1st blade passing frequency (BPF) and its harmonics, while additional broadband components, mainly linked with the blade shape, the developed engine power, and the turbulent boundary layer (TBL), also contribute to the excitation levels. The vibrations problem takes on particular relevance in the case of composite structures. The laminates in fact could exert damping levels generally lower than metallic structures, where the greater amount of bolted joints allow for dissipating more vibration energy. The prediction and reduction of aircraft vibration levels are therefore significant considerations for conventional propeller aircrafts now entering the commercial market as well as for models currently being developed. In the Clean Sky 2 framework, the present study focuses on a practical case inherent to the AIRBUS-Racer program aiming to design and develop a multi-tasking fast rotorcraft. This paper defines a finite elements (FE)-based procedure for the characterization of the vibration levels of a main landing gear (MLG) composite door with respect to the expected operating tonal loads. A parametric assessment was carried out to evaluate the principal modal parameters (transfer functions and respective resonance frequencies, mode shapes, and damping coefficients) of the landing gear-door assembly in order to achieve reduced vibration levels. Based on the FE analysis results, the influence of the extra-damping, location, and number of ballast elements, the boundary conditions were investigated with respect to failure scenarios of the kinematic line opening the study towards aeroelastic evaluations. Further experimental ground test results serve as a validation database for the prediction numerical methods representative of the composite door dynamic response