Transplant recipients, who receive therapeutic immunosuppression to prevent graft rejection, are characterized by high coronavirus disease 2019 (COVID-19)-related mortality and defective response to ...vaccines. We observed that previous infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but not the standard two-dose regimen of vaccination, provided protection against symptomatic COVID-19 in kidney transplant recipients. We therefore compared the cellular and humoral immune responses of these two groups of patients. Neutralizing anti-receptor-binding domain (RBD) immunoglobulin G (IgG) antibodies were identified as the primary correlate of protection for transplant recipients. Analysis of virus-specific B and T cell responses suggested that the generation of neutralizing anti-RBD IgG may have depended on cognate T-B cell interactions that took place in germinal center, potentially acting as a limiting checkpoint. High-dose mycophenolate mofetil, an immunosuppressive drug, was associated with fewer antigen-specific B and T follicular helper (T
) cells after vaccination; this was not observed in patients recently infected with SARS-CoV-2. Last, we observed that, in two independent prospective cohorts, administration of a third dose of SARS-CoV-2 mRNA vaccine restored neutralizing titers of anti-RBD IgG in about 40% of individuals who had not previously responded to two doses of vaccine. Together, these findings suggest that a third dose of SARS-CoV-2 mRNA vaccine improves the RBD-specific responses of transplant patients treated with immunosuppressive drugs.
Abstract
Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. High suspended sediment loads, often generated from eroding agricultural landscapes, are ...known to degrade downstream environments. Accordingly, there is a need to understand soil erosion dynamics during flood events. Suspended sediment was therefore sampled in the river network and at tile drain outlets during five flood events in a lowland drained catchment in France. Source and sediment fallout radionuclide concentrations (
7
Be,
210
Pb
xs
) were measured to quantify both the fraction of recently eroded particles transported during flood events and their residence time. Results indicate that the mean fraction of recently eroded sediment, estimated for the entire Louroux catchment, increased from 45 ± 20% to 80 ± 20% between December 2013 and February 2014, and from 65 ± 20% to 80 ± 20% in January 2016. These results demonstrate an initial flush of sediment previously accumulated in the river channel before the increasing supply of sediment recently eroded from the hillslopes during subsequent events. This research highlights the utility of coupling continuous river monitoring and fallout radionuclide measurements to increase our understanding of sediment dynamics and improve the management of soil and water resources in agricultural catchments.
Purpose
To compare everolimus (EVR) plus low-dose tacrolimus (TAC) with mycophenolic acid (MPA) plus standard-dose TAC with regards to rates of cytomegalovirus (CMV) disease in de novo ...kidney-transplant recipients (KTRs).
Methods
This single-center retrospective study included 187 de novo KTRs; 59 patients (31.6%) received EVR/low-dose TAC (group 1); 128 patients (68.4%) received MPA with standard-dose TAC (group 2). All received anti-thymocyte globulins as the induction therapy, and steroid-sparing strategy. Valganciclovir prophylaxis was mandatory for CMV D+/R− KTRs (seronegative recipients of a seropositive donor) in both groups and for R+ seropositive recipients (only in group 2).
Results
The 2-year incidence of CMV disease was low and comparable between groups: 6.8% and 7.0% in groups 1 and 2, respectively (
p
= 0.94). There was no statistical difference in CMV serostatus (
p
= 1). However, CMV disease tended to be less frequent, though not statistically different, in R+ KTRs receiving EVR without prophylaxis (3.7% vs. 8.5% in groups 1 and 2, respectively) and in patients without EVR discontinuation (2.6% vs. 6.9% in patients who did not discontinue MPA (
p
= 0.29). Two-year graft function was good and comparable between groups (median eGFR of 54.2 and 53.0 mL/min in groups 1 and 2, respectively;
p
= 0.47); incidence of immunological events was low. Significantly more patients in group 1 discontinued EVR because of adverse events than patients that discontinued MPA in group 2 (35.6% in group 1 vs. 10.2% in group 2;
p
< 0.001).
Conclusions
Everolimus plus low-dose TAC given to de novo KTRs was associated with low rates of CMV disease, especially in R+ patients with no CMV prophylaxis.
We herein describe the first case of thrombotic microangiopathy (TMA) which was related to Shiga toxin producing-Escherichia Coli Hemolytic and Uremic Syndrome (STEC-HUS) after lung transplantation. ...His maintenance immunosuppression relied on tacrolimus plus mycophenolic acid. TMA was treated with plasma exchanges (PE) (fresh frozen plasma substitution). After five days of PE, platelets count and lactate dehydrogenase level normalized, whereas hemoglobin continued to gradually decrease and no improvement in kidney function was observed. After seven PE sessions, all TMA biological signs resolved. However, kidney function did not improve, and the patient still required chronic dialysis.
The dataset contains the spatial data needed to build the network of least cost camel paths between archaeological sites and watering places in the Egyptian Eastern Desert during the Ptolemaic and ...Roman periods. It includes the sites to be linked, the travel factors (topography, navigation and terrain surface), the modern traveler routes used for training and model validation, and the outputs. Data processing models, made on ArcGIS 10.5, are available. Data and analyses for model calibration and validation to assess its quality are also provided. The objective of this dataset is to be able to reproduce the network created in the Egyptian Eastern Desert and facilitate the application of the approach to other study areas. Although the input data is based on the Egyptian Eastern Desert, the method is nevertheless reproducible using the data processing models developed. Paper linked with the data: Manière, L., Crépy, M., Redon, B. (2021) Building a Model to reconstruct the Hellenistic and Roman Road Networks of the Eastern Desert of Egypt, a Semi-Empirical Approach Based on Modern Travelers’ Itineraries. Journal of Computer Applications in Archaeology. In review.
Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. High suspended sediment loads, often generated from eroding agricultural landscapes, are known to ...degrade downstream environments. Accordingly, there is a need to identify suspended sediment sources and to investigate their dynamics. Here, soil and sediment strontium isotopic ratios were used to examine suspended sediment sources and dynamics in a lowland drained catchment in France.
Suspended sediment (n=14) was collected in stream and at tile drain (n=4) outlets during three flood events between December 2013 and February 2014. Potential source soils (n=28) representative of the carbonate and silicate substrates found in the catchment were sampled and analyzed. Strontium isotopic ratios (87Sr/86Sr) were measured in different particle size fractions (<2μm, <63μm and <2mm).
Soil 87Sr/86Sr ratios significantly discriminated between source samples classified as carbonate (0.712625 to 0.717815) and silicate (0.719287 to 0.724631) soils. 87Sr/86Sr ratios measured in suspended sediment (0.713660 to 0.720571) reflect variations in source contributions during different hydrological conditions. The 87Sr/86Sr ratios varied in the different fractions of soil samples (i.e. <2μm, <63μm and <2mm) and in suspended sediment samples. Suspended sediment was interpreted as a mixture of two end-members, with the dominant contribution of the <2μm fraction of soil samples occurring during small scale flood events and the <2mm fraction during more intense flood events. Modelling results indicate that carbonate source soil contributions are variable, with their highest contributions occurring during the two first flood events compared to the last flood event.
The results also show that the tile drainage system enhances the connectivity between cultivated hillslopes and the river network, providing a preferential pathway for fine (<2μm) particles. This study demonstrates the potential of using strontium isotopic ratios to examine the variations of suspended sediment sources in drained catchments with contrasting carbonate and silicate sources. More importantly, the results highlight the need to improve the management of sediment exported from tile drains in similar agricultural environments, as they were demonstrated to transfer very fine material to the riverine environment.
•Soil samples were discriminated according to catchment substrate (i.e. carbonate and silicate)•87Sr/86Sr ratios of suspended sediment varied depending on hydrological conditions•Different particle size fractions were modelled for different flood intensities (i.e. <2mm and <2μm)•Carbonate soils dominated two less intense flood events (63%) whereas silicate soils dominated a higher intensity flood (72%)•Field drainage systems likely enhance the hillslope to river connectivity, particularly for the finest particles
The Egyptian Eastern Desert, the part of the Sahara Desert that connects the Nile and the Red Sea, is rich in natural resources and meshed with multiple networks. The adoption of the camel as the ...main mode of transportation in the 1st millennium BC, faster and with a greater load capacity than humans or donkeys, dramatically changed the logistics used to cross this difficult terrain. Our objective, therefore, is to understand and reconstruct circulation in the region during Antiquity through location factors and the evolution of roads. For this purpose, a least-cost network specific to camel movements has been created for this arid and mountainous region.The network is based on the reconstructed itineraries of modern travelers (18th and 19th centuries) who crossed the region under similar conditions to ancient ones. These routes and the travelers’ diaries have enabled us to analyze the main travel constraints; they provide a set of data to calibrate the different movement factors of camel caravans and to validate the calculated least cost paths. The modeled network takes into account transport infrastructures, navigation conditions in plain areas, difficulties of the terrain surface, and the topographical constraints specific to camels.This methodological paper details our approach from the description of movement factors, their mapping, and their use in least cost algorithms to the creation of a network covering 253 archaeological sites and 204 desert watering places. It aims to provide the archaeological and GIS communities with the method and tools to reproduce itineraries based on the hypotheses of movement and empirical data. For this purpose, the data is available and documented by a data paper.
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