Loss of SOCS3 expression in T cells reveals a regulatory role for interleukin-17 in atherosclerosis

Atherosclerosis is an inflammatory vascular disease responsible for the first cause of mortality worldwide. Recent studies have clearly highlighted the critical role of the immunoinflammatory balance in the modulation of disease development and progression. However, the immunoregulatory pathways that control atherosclerosis remain largely unknown. We show that loss of suppressor of cytokine signaling (SOCS) 3 in T cells increases both interleukin (IL)-17 and IL-10 production, induces an antiinflammatory macrophage phenotype, and leads to unexpected IL-17–dependent reduction in lesion development and vascular inflammation. In vivo administration of IL-17 reduces endothelial vascular cell adhesion molecule–1 expression and vascular T cell infiltration, and significantly limits atherosclerotic lesion development. In contrast, overexpression of SOCS3 in T cells reduces IL-17 and accelerates atherosclerosis. We also show that in human lesions, increased levels of signal transducer and activator of transcription (STAT) 3 phosphorylation and IL-17 are associated with a stable plaque phenotype. These results identify novel SOCS3-controlled IL-17 regulatory pathways in atherosclerosis and may have important implications for the understanding of the increased susceptibility to vascular inflammation in patients with dominant-negative STAT3 mutations and defective Th17 cell differentiation

Genetic Engineering of Trypanosoma (Dutonella) vivax and In Vitro Differentiation under Axenic Conditions

Trypanosoma vivax is one of the most common parasites responsible for animal trypanosomosis, and although this disease is widespread in Africa and Latin America, very few studies have been conducted on the parasite's biology. This is in part due to the fact that no reproducible experimental methods had been developed to maintain the different evolutive forms of this trypanosome under laboratory conditions. Appropriate protocols were developed in the 1990s for the axenic maintenance of three major animal Trypanosoma species: T. b. brucei, T. congolense and T. vivax. These pioneer studies rapidly led to the successful genetic manipulation of T. b. brucei and T. congolense. Advances were made in the understanding of these parasites' biology and virulence, and new drug targets were identified. By contrast, challenging in vitro conditions have been developed for T. vivax in the past, and this per se has contributed to defer both its genetic manipulation and subsequent gene function studies. Here we report on the optimization of non-infective T. vivax epimastigote axenic cultures and on the process of parasite in vitro differentiation into metacyclic infective forms. We have also constructed the first T. vivax specific expression vector that drives constitutive expression of the luciferase reporter gene. This vector was then used to establish and optimize epimastigote transfection. We then developed highly reproducible conditions that can be used to obtain and select stably transfected mutants that continue metacyclogenesis and are infectious in immunocompetent rodents

Near real-time determination of B.1.1.7 in proportion to total SARS-CoV-2 viral load in wastewater using an allele-specific primer extension PCR strategy

"The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome corona- virus 2 (SARS-CoV-2) has claimed millions of lives to date. Antigenic drift has resulted in viral variants with putatively greater transmissibility, virulence, or both. Early and near real-time detection of these variants of concern (VOC) and the ability to accurately follow their incidence and prevalence in communities is wanting. Wastewater-based epidemiology (WBE), which uses nucleic acid amplification tests to detect viral fragments, is a reliable proxy of COVID-19 incidence and prevalence, and thus offers the potential to monitor VOC viral load in a given population. Here, we describe and validate a primer extension PCR strategy targeting a signature mutation in the N gene of SARS-CoV-2. This allows quantification of B.1.1.7 versus non-B.1.1.7 allele frequency in wastewater without the need to employ quantitative RT-PCR standard curves. We show that the wastewater B.1.1.7 profile correlates with its clinical counterpart and benefits from a near real-time and facile data collection and reporting pipeline. This assay can be quickly implemented within a current SARS-CoV-2 WBE framework with minimal cost; allowing early and contemporaneous estimates of B.1.1.7 community transmission prior to, or in lieu of, clinical screening and identification. Our study demonstrates that this strategy can provide public health units with an additional and much needed tool to rapidly triangulate VOC incidence/prevalence with high sensitivity and lineage specificity"National Microbiology Laboratory||Water Services at the Cities of Ottawa and Barrie||Ottawa Public Health||Simcoe Muskoka District Health Unit|| Public Health Ontario||Ontario Wastewater Surveillance Initiativ

Podium - Personal online dosimetry using computational methods

Individual monitoring of radiation workers is essential to ensure compliance with official dose limits and to allow application of the ALARA principle. Routine monitoring of staff is usually performed by means of passive dosimeters. However, current personal dosimeters are subject to large uncertainties, especially in heterogeneous fields, like those found in interventional radiology (IR). Within the PODIUM (Personal Online DosImetry Using computational Methods) research project, a user-friendly application was developed based on MCNP Monte-Carlo code to calculate doses to the staff in IR. The application uses both the data of motion tracking system to generate the position of the operator and the data from the Radiation Dose Structure Report (RDSR) from the imaging device to generate time-dependent parameters of the radiation source. The results of the first clinical validation of the system show good agreement within 10-40% between simulated Hp(10) with MCNP and measured Hp(10) with electronic personal dosimeter worn above the lead apron. Some challenges and limitations remain, however, the results from the two-year proof-of-concept PODIUM project are promising. We have shown that the technology is now available for tracking staff position and calculating their dose using detailed phantoms, without the need to wear an individual dosimeter.PODIUM: Personal Online DosImetry Using computational Method

Personal Dose Computation with the Aid of Staff Monitoring systems based on 3D Depth Cameras

For more than 50 years, passive dosimeters have been used to assess the dose to workers occupationally exposed to ionizing radiation. Such dosimeters are designed to measure the operational quantity Hp(10) as an estimate of the effective dose, E, which is a quantitative expression of the “radiation detriment” that cannot be measured directly. With these dosimeters, the results are mostly known only after some time, and wearing a dosimeter is often seen as a burden by some workers. Furthermore, the uncertainties associated with the present dosimeters (within a factor of 1.5 or 2 from the real value) are not negligible. In line with the current move to more real-time personal dose monitoring, we are working towards an innovative approach based on computational methods to determine occupational exposures. The aim of this research is to calculate doses to workers instead of measuring them. For this, the spatial radiation field, including energy and angular distribution, needs to be known. The real movement of the persons in a given workplace can be monitored in real-time using Time-of-Flight cameras and flexible computational phantoms representing the workers anatomy can be positioned using the tracking information. Finally, all this input data should be transferred to a tool, using Monte Carlo techniques to calculate the doses to the workers. As a first step, a tool used to track a person in 3D coordinates using Microsoft® Kinect™ was developed. The tool, which is utilizing the skeleton tracking algorithm embedded in the Kinect SDK from Microsoft, is capable of correctly tracking the worker movement in real-time. A series of validation experiments were performed to test the tracking tool and the dose calculation method. An anthropomorphic phantom was positioned on a moveable table in the horizontal irradiator of the Laboratory for Nuclear Calibration (LNK) at SCK•CEN. The phantom was moved to different distances from a Cs-137 source. The position of the phantom was monitored with the Kinect™ and the coordinates recorded. The dose to the phantom was calculated using different methods: 1. Using the reference values from the calibration facility (LNK), 2. Using VISIPLAN-3D: An analytical dose assessment tool developed at SCK•CEN, 3. Using MCNPX Monte-Carlo simulations, and 4. Using InstaDose® dosimeters based on direct ion storage technology. A comparison was made between each method and results showed good agreement between the reference, the measured and the calculated dose. This experiment was repeated with different degrees of complexity of movement of the phantom. This first test proved the validity of the methodology used

Calcul de dose personnel avec l'aide du système de surveillance du personnel basé sur les 3D caméras de profondeur

For more than 50 years, passive dosimeters have been used to assess the dose to workers occupationally exposed to ionizing radiation. Such dosimeters are designed to measure the operational quantity Hp(10) as an estimate of the effective dose, E, which is a quantitative expression of the “radiation detriment” that cannot be measured directly. With these dosimeters, the results are mostly known only after some time, and wearing a dosimeter is often seen as a burden by some workers. Furthermore, the uncertainties associated with the present dosimeters (within a factor of 1.5 or 2 from the real value) are not negligible. In line with the current move to more real time personal dose monitoring, we are working towards an innovative approach based on computational methods to determine occupational exposures. The aim of this research is to calculate doses to workers instead of measuring them. For this, the spatial radiation field, including energy and angular distribution, needs to be known. The real movement of the persons in a given workplace can be monitored in real-time using Time-of-Flight cameras and flexible computational phantoms representing the workers anatomy can be positioned using the tracking information. Finally, all this input data should be transferred to a tool, using Monte Carlo techniques to calculate the doses to the workers. As a first step, a tool used to track a person in 3D coordinates using Microsoft® Kinect™ was developed. The tool, which is utilizing the skeleton tracking algorithm embedded in the Kinect SDK from Microsoft, is capable of correctly tracking the worker movement in real-time. A series of validation experiments were performed to test the tracking tool and the dose calculation method. An anthropomorphic phantom was positioned on a moveable table in the horizontal irradiator of the Laboratory for Nuclear Calibration (LNK) at SCK•CEN. The phantom was moved to different distances from a Cs-137 source. The position of the phantom was monitored with the Kinect™ and the coordinates recorded. The dose to the phantom was calculated using different methods: 1. Using the reference values from the calibration facility (LNK), 2. Using VISIPLAN-3D: An analytical dose assessment tool developed at SCK•CEN, 3. Using MCNPX Monte-Carlo simulations, and 4. Using InstaDose® dosimeters based on direct ion storage technology. A comparison was made between each method and results showed good agreement between the reference, the measured and the calculated dose. This experiment was repeated with different degrees of complexity of movement of the phantom. This first test proved the validity of the methodology used

First steps towards online Personal Dosimetry Using Computational Methods in Interventional Radiology: operator’s position tracking and simulation input generation

peer reviewedInterventional radiologists/cardiologists are repeatedly exposed to low radiation doses which makes them the group of the highest occupational exposure and put them at high risk of stochastic effects. Routine monitoring of staff is usually performed by means of passive dosimeters. However, current personal dosimeters are subject to large uncertainties, especially in non-homogeneous fields, like those found in interventional cardiology (IC). Within the PODIUM (Personal Online DosImetry Using computational Methods) research project, a user-friendly tool was developed based on MCNP code to calculate doses to the staff in IC. The application uses both the data of motion tracking system to generate the position of the operator and the data from the Radiation Dose Structure Report (RDSR) from the imaging device to generate time-dependent parameters of the radiation source. The results of the first clinical validation of the system show a difference of about 50% between simulated Hp(10) with MCNP and measured Hp(10) with electronic personal dosimeter worn above the lead apron.Introduction With this work we present an innovative system for calculating occupational doses, as it is now being developed within the PODIUM (Personal Online DosImetry Using computational Methods) project. Individual monitoring of workers is essential to follow up regulatory dose limits and to apply the ALARA principle. However, current personal dosimeters are subject to large uncertainties, especially in non-homogeneous fields, like those found interventional radiology/cardiology. Workers in these fields also need to wear several dosimeters (extremity, eye lens, above/below apron), which causes practical problems. As the capabilities of computational methods are increasing exponentially, it will become feasible to use pure computations to calculate doses in place of physical dosimeters. Methods In our concept system, operational and protection quantities are calculated by fast Monte Carlo methods. Our dose calculation accounts for the real radiation field (including fluence, energy and angular distributions) and for the relative position of different body parts of the worker. The real movements of exposed workers are captured using depth cameras. This information is translated to a flexible anthropomorphic phantom, and then in Monte-Carlo simulations. For the moment this is done off-line, after the procedure is finished, and the parameters of the procedure are collected. Results For validating our system, we performed tests in interventional radiology (IR) rooms. In total, we followed 15 procedures in Cath-labs at UZ-VUB and CHU- Liège. An accurate analysis of the staff position was performed, and as a first step, we compared simulated Hp(10) and measured Hp(10) with electronic personal dosimeter (EPD) during an angiography procedure for some of these procedures. The results showed good agreement between the calculated doses and the ones measured by the EPD dosimeter. Conclusions With this work, we show that simulating worker doses based on tracking systems and flexible phantoms is possible. This method has big advantages in interventional radiology workplaces where the fields are non-homogeneous and doses to staff can be relatively high. This method can also help in ALARA applications and for education and training.PODIUM: Personal Online DosImetry Using computational Method

Development and Validation of Online Personal Dosimetry Application Using Computational Method for Interventional Cardiology

Introduction Interventional cardiologists are often occupationally exposed to low radiation doses which put them at risk of stochastic radiation induced detriments. Therefore, individual monitoring of medical staff is essential to follow up regulatory dose limits and to apply the ALARA principle. However, current personal dosimeters are subject to large uncertainties, especially in non-homogeneous fields, like those found interventional radiology/cardiology. In these workplaces, medical staff should wear several dosimeters (extremity, eye lens, above/below apron) for a proper monitoring. However, the use of multiple dosimeters is unpractical, and in some cases it could hinder the work of the physicians (like in the case of finger dosimeters). As the capabilities of computational methods are increasing exponentially, it will become feasible to use pure computations to calculate doses in place of physical dosimeters. With this work, we present the current state of development of an innovative tool for calculating occupational doses using Monte-Carlo methods. The system is being developed within the PODIUM (Personal Online DosImetry Using computational Methods) research project. Materials & Methods In typical interventional radiology/cardiology scenarios, operators are exposed to non-homogeneous scatter radiation field coming from the body of the patient. The anisotropy is higher while working close by to the patient for performing manipulations. The two main inputs to our computational dosimetry system are: a) the spatiotemporal distribution of the scattered radiation field, including its intensity, its energy and its angular distributions; b) the relative position and pose of the operator in the scatter field. 1. Radiation field parameters. The scatter radiation is dependent on a number of factors such as: primary beam intensity, beam projection angle and patient thickness. Acquiring information about the primary beam and the patient can help reproducing the scatter field computationally. Imaging parameters includes kVp, filtration, collimation and beam projection are used to simulate the primary beam and its scattered field in Monte-Carlo simulations. At this stage, such information is obtained from a summary dose report after each procedure. The measured dose-area product (DAP) value allows to normalize the simulated relative doses (eV/g per particle) to the equivalent absolute dose units. 2. Operator motion tracking. The main input to compute doses to operators is the position and pose of the body of the operator relative to the X-ray beam and to the patient. Our system provides an indoor tracking system for tracking the position and the posture of the workers. The system is constituted by a Microsoft Kinect v2 Time-Of-Flight (TOF) camera and by an acquisition software package. The body skeleton information provided by the tracking system is then used to position a phantom. At the current stage, the system represents a proof-of-concept and calculations are done off-line, after the procedure is finished, and the parameters of the procedure are collected. For validating our system, we performed tests in two interventional radiology (IR) rooms. In total, we followed 15 procedures in Cath-labs at UZ-VUB and CHU- ULiège hospitals. The Monte Carlo N-particle code (MCNPX 2.7) code [1] is used in our method for modelling and dosimetry calculations. The body skeleton information of the main operator provided by the tracking system is used to estimate the position of a dosimeter on the chest level in the simulations. Results An accurate analysis of the staff position was performed, and as a first step, we compared simulated Hp(10) with MCNP and measured Hp(10) with electronic personal dosimeter (EPD) Mk2.3 from Thermo Fisher Scientific worn above the lead apron during an angiography procedure for some of these procedures. The results showed good agreement with less than 5% difference between the calculated doses and the ones measured by the EPD dosimeter. The differences found in our simulations are easily explained by the uncertainties of the EPD dosemeter. In fact, the study performed by Clairand et al. [2] showed that the EPD Mk2.3 has a variation on the response within 30-40% due to the energy and angular response with the effect of the pulse frequency of the x-ray beam in interventional radiology fields. In addition, simulations provided extra information about the eye lens dose Hp(3) to the operator during one procedure which shows the high spread of the ratio Hp(3)/Hp(10) between 0.48 to 1.75 for different beam projections due to field inhomogeneity. Conclusions and future work With this work, we show that simulating worker doses based on tracking systems and flexible phantoms in Monte-Carlo codes is possible. This method has big advantages in interventional radiology workplaces where the radiation fields are non-homogeneous and doses to staff can be relatively high. This method can also help for the application of the ALARA principle and for education and training of medical staff. For the future, we will transfer the skeletal data to the Realistic Anthropomorphic Flexible computational phantom [3] in Monte-Carlo simulation to calculate organ doses. References [1] D.B. Pelowitz, Ed., "MCNPX User’s Manual Version 2.7.0" LA-CP-11-00438 (2011). [2] Clairand et al. “Use of active personal dosemeters in interventional radiology and cardiology: Tests in laboratory conditions and recommendations - ORAMED project”, Radiation Measurements, Volume 46, Issue 11, (2011). [3] Lombardo et al. “Development and validation of the realistic anthropomorphic flexible (RAF) phantom”, Health Physics, 114:489–499, 05 (2018). Acknowledgements This project is funded by the CONCERT - European Joint Programme for the Integration of Radiation Protection Research 2014-2018 under grant agreement No. 662287.PODIUM: Personal Online DosImetry Using computational Method

Cellulose nanocrystals from agricultural residues (Eichhornia crassipes): Extraction and characterization

International audienceExtraction of cellulose nanocrystals (CNCs) from agro-residues has received much attention, not only for their unique properties supporting a wide range of potential applications, but also their limited risk to global climate change. This research was conducted to assess Nile roses (Eichhornia crassipes) fibers as a natural biomass to extract CNCs through an acid hydrolysis approach. Nile roses fibers (NRFs) were initially subjected to alkaline (pulping) and bleaching pretreatments. Microcrystalline cellulose (MCC) was used as control in comparison to Nile rose based samples. All samples underwent acid hydrolysis process at a mild temperature (45 °C). The impact of extraction durations ranging from 5 to 30 min on the morphology structure and crystallinity index of the prepared CNCs was investigated. The prepared CNCs were subjected to various characterization techniques, namely: X-ray diffraction (XRD), FT-IR analysis, Transmission electron microscopy (TEM), and X-ray Photoelectron spectroscopy (XPS). The outcomes obtained by XRD showed that the crystallinity index increased as the duration of acid hydrolysis was prolonged up to 10 min, and then decreased, indicating optimal conditions for the dissolution of amorphous zones of cellulose before eroding the crystallized domains. These data were confirmed by FT-IR spectroscopy. However, a minor effect of hydrolysis duration on the degree of crystallinity was noticed for MCC based samples. TEM images illustrated that a spherical morphology of CNCs was formed as a result of 30 min acid hydrolysis, highlighting the optimal 20 min acid hydrolysis to obtain a fibrillar structure. The XPS study demonstrated that the main constituents of extracted CNCs were carbon and oxygen