Etude des récepteurs NK et leurs ligands au cours des hémopathies malignes et après greffe des cellules souches hématopoïetiques chez l'homme

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Effect of soil drying on FT-IR spectroscopic analysis: a methodological study in Luxembourg

Optimum soil quality is a goal to be achieved in agriculture and forestry and in order to maintain a sustainable equilibrium of ecosystems. The evaluation of various parameters influencing the soil’s structure, fertility or even its chemical, physical or biological properties, like for instance soil organic matter, often relies on time-consuming and cost-intensive labwork. Fourier Transform Infrared (FT-IR) spectroscopy, however, has highly contributed to rapidly and cost-effectively assess these different parameters. Especially the mid-infrared (MIR) range (4000-400cm-1) has proven to be an effective tool to predict soil properties. Additionally, MIR spectroscopy represents a qualitative analysis and renders spectral interpretation less complex by easily attributing peaks to organic or mineral compounds on the spectrum. Our research focuses on characterizing various soil compounds (water-extractable organic matter and lipids) through MIR spectral analysis. The present study specifically investigates the effect of various drying conditions on soils by Fourier Transform infrared spectroscopy in attenuated total reflectance (ATR) mode. The OL and A horizons of five representative soils of Luxembourg were collected: a Stagnic cambisol (Humic, Dystric), a Haplic Acrisol (Arenic), a Stagnic Albeluvisol (Dystric, Siltic), a Cambic Leptosol (Calcaric) and a Haplic Cambisol (Eutric). Field-moist soil samples were directly sieved in a 2mm mesh and conditioned in accordance with the different drying procedures realized during this study, namely freeze-drying, oven-drying (25, 40, 80 and 105°C) and air-drying (20°C). The spectral analyses were performed after incorporation of KBr pellets on a Bruker Hyperion 2000 (Bruker Optik Gmbh, Ettlingen, Germany) Fourier Transform-Infrared Spectrometer (FT-IR) in Attenuated Total Reflectance mode (ATR). For each pellet, three spectra were recorded at different locations, in order to evaluate the reproducibility of the method. Additional conventional soil analyses were realized: pH (H2O, KCl, CaCl2), exchange capacity (Cohex) and related exchangeable cations, particle size analysis and CHNS elemental analysis, including the distinction between total and organic carbon contents, by means of acidic pretreatment of samples (HCl 2N). The outcome of this study shall define an optimal drying procedure for soil organic matter analysis coupled with infrared spectrometry. Indeed, traces of water in soil samples are known to produce broad bands around 3500cm- 1, which may mask relevant peaks related to soil. The expected results would show a significant attenuation or even an absence of the water band, depending on the pretreatment applied. In addition, this work will also be focused on the impact of the drying procedure on the spectral bands attributable to soil organic matter, possibly due to SOM degradation. Furthermore, the results from the preferred method should be reproducible independently from the type of soil chosen

Effect of soil drying on FT-IR spectroscopic analysis: a methodological study in Luxembourg

Optimum soil quality is a goal to be achieved in agriculture and forestry and in order to maintain a sustainable equilibrium of ecosystems. The evaluation of various parameters influencing the soil’s structure, fertility or even its chemical, physical or biological properties, like for instance soil organic matter, often relies on time-consuming and cost-intensive labwork. Fourier Transform Infrared (FT-IR) spectroscopy, however, has highly contributed to rapidly and cost-effectively assess these different parameters. Especially the mid-infrared (MIR) range (4000-400cm-1) has proven to be an effective tool to predict soil properties. Additionally, MIR spectroscopy represents a qualitative analysis and renders spectral interpretation less complex by easily attributing peaks to organic or mineral compounds on the spectrum. Our research focuses on characterizing various soil compounds (water-extractable organic matter and lipids) through MIR spectral analysis. The present study specifically investigates the effect of various drying conditions on soils by Fourier Transform infrared spectroscopy in attenuated total reflectance (ATR) mode. The OL and A horizons of five representative soils of Luxembourg were collected: a Stagnic cambisol (Humic, Dystric), a Haplic Acrisol (Arenic), a Stagnic Albeluvisol (Dystric, Siltic), a Cambic Leptosol (Calcaric) and a Haplic Cambisol (Eutric). Field-moist soil samples were directly sieved in a 2mm mesh and conditioned in accordance with the different drying procedures realized during this study, namely freeze-drying, oven-drying (25, 40, 80 and 105°C) and air-drying (20°C). The spectral analyses were performed after incorporation of KBr pellets on a Bruker Hyperion 2000 (Bruker Optik Gmbh, Ettlingen, Germany) Fourier Transform-Infrared Spectrometer (FT-IR) in Attenuated Total Reflectance mode (ATR). For each pellet, three spectra were recorded at different locations, in order to evaluate the reproducibility of the method. Additional conventional soil analyses were realized: pH (H2O, KCl, CaCl2), exchange capacity (Cohex) and related exchangeable cations, particle size analysis and CHNS elemental analysis, including the distinction between total and organic carbon contents, by means of acidic pretreatment of samples (HCl 2N). The outcome of this study shall define an optimal drying procedure for soil organic matter analysis coupled with infrared spectrometry. Indeed, traces of water in soil samples are known to produce broad bands around 3500cm- 1, which may mask relevant peaks related to soil. The expected results would show a significant attenuation or even an absence of the water band, depending on the pretreatment applied. In addition, this work will also be focused on the impact of the drying procedure on the spectral bands attributable to soil organic matter, possibly due to SOM degradation. Furthermore, the results from the preferred method should be reproducible independently from the type of soil chosen

Letermovir for Secondary Prophylaxis of Cytomegalovirus Infection and Disease after Allogeneic Hematopoietic Cell Transplantation: Results from the French Compassionate Program

International audienc

Spike Gene Evolution and Immune Escape Mutations in Patients with Mild or Moderate Forms of COVID-19 and Treated with Monoclonal Antibodies Therapies

We explored the molecular evolution of the spike gene after the administration of anti-spike monoclonal antibodies in patients with mild or moderate forms of COVID-19. Four out of the 13 patients acquired a mutation during follow-up; two mutations (G1204E and E406G) appeared as a mixture without clinical impact, while the Q493R mutation emerged in two patients (one receiving bamlanivimab and one receiving bamlanivimab/etesevimab) with fatal outcomes. Careful virological monitoring of patients treated with mAbs should be performed, especially in immunosuppressed patients

Allogeneic Stem Cell Transplantation in Therapy-Related Myelodysplasia after Autologous Transplantation for Lymphoma: A Retrospective Study of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy

Therapy-related myelodysplastic syndrome (t-MDS) after autologous stem cell transplantation (ASCT) is a rare complication with no curative option. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) may be considered for eligible patients and has been understudied in t-MDS. We report 47 consecutive patients with t-MDS after an ASCT who underwent allo-HSCT with a median age of 58 years (range, 30 to 71 years) at transplantation and a median follow-up of 22 months (range, 0.7 to 107). The median overall survival (OS) was 6.9 months (95% confidence interval [CI], 0 to 19 months). OS rates were 45% (29% to 60%) and 30% (15% to 45%) at 1 and 3 years after transplantation, respectively. On univariate analysis, prior therapy for t-MDS before allo-HSCT (P = .02) and mismatched donors (P = .004) were associated with poor OS. Three-year nonrelapse mortality (NRM) and relapse rates were 44% (25% to 63%) and 41% (22% to 61%), respectively. Mismatched donors (P < .001) were associated with higher NRM and a high-risk MDS (P = .008) with a higher relapse risk. On multivariate analysis, HLA mismatch was associated with higher NRM (hazard ratio, 6.21; 95% CI, 1.63 to 23.62; P = .007). In conclusion, our results suggest that one third of the patients who develop t-MDS after an ASCT for lymphoma are cured after an allo-HSCT. The use of mismatched donors with standard graft-versus-host disease prophylaxis should be avoided in such an indication for allo-HSCT. It will be worthwhile to see if the implementation of cyclophosphamide post-transplantation will improve the outcome with mismatched donors

Immune stimulation during chemotherapy increases incidence of acute graft versus host disease in acute myeloid leukemia: A study on behalf of SFGM-TC and ALFA

IF 2.501International audience60-70% of AML patients have an indication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) during their treatment. Graft versus host disease (GvHD), the major cause of mortality and comorbidities post-transplantation, develops by immunological mechanism and decides greatly prognosis and quality of life (QoL) of graft recipient. Current GvHD prophylaxis is not personalized. Infections, toxicities and leukemic infiltration complicate the first chemotherapy phases prior to allo-HSCT. They, to certain extent, induce local immune stimulation. Impact of immune stimulation of this period on incidence of GvHD has not been evaluated. We retrospectively studied 238 AML patients transplanted at first remission from 21 French centers in the ALFA-0702 protocol and found that cutaneous and digestive immune stimulation during induction increases the incidence of skin and gut aGVHD, respectively. Furthermore, prolonged febrile duration correlates with elevated incidence of grade II-IV aGvHD. Thus, we identified a group of patients with higher risk of aGvHD. The benefit of personalized GvHD prophylaxis should be explored in a prospective cohort to decrease incidence of aGvHD in these patients and improve their QoLs

One-month humoral response following two or three doses of mRNA Covid-19 vaccines as primary vaccination in specific populations in France: first results from the ANRS0001S COV-POPART cohort

International audienceObjectives: We aimed to investigate the one-month humoral response to two or three doses as primary vaccination in specific populations compared to healthy adults.Methods: ANRS0001S-COV-POPART (NCT04824651) is a French nationwide multicenter prospective observational cohort study assessing the immune response to Covid-19 vaccines routinely administered to 11 subgroups of patients with chronic conditions and two control groups. Patients and controls who had received at least two vaccine doses and whose results at one month after the second dose were available have been included. Humoral response was assessed at 1-month post first dose, post second dose and post third dose (if applicable), through the percentage of responders (positive anti-Spike SARS-CoV-2 IgG antibodies, geometric means of anti-Spike SARS-CoV-2 IgG antibodies (ELISA) and proportion of participants with anti-SARS-CoV-2-specific neutralizing antibodies (in vitro neutralization assay for the original SARS-CoV-2 strain). All analyses were centralized.Results: We included 4091 participants in this analysis: 2979 participants from specific subpopulations and 1112 controls. Only 522 (17.5%) of the specific populations received 3 doses as primary vaccination regimen. Patients living with HIV, cancer and diabetic patients had high rates of responders after two doses while solid organ transplant (SOT), allogeneic hematopoietic stem cell transplant (HSCT) and hypogammaglobulinemic patients had the lowest percentage of responders (35.9% [95%CI: 29.2; 43.0], 57.4% [48.1; 66.3]) and 77.1% [65.6; 86.3] respectively). In those who received a third dose, the rate of responders reached 54.2% [42.9-65.2] (vs. 32.3% (16.7-51.4) after 2 doses) in SOT and 73.9% [58.9-85.7) (vs. 56.1% [46.2-65.7] after 2 doses) in HSCT. Similar results were found with anti-SARS-CoV-2-specific neutralizing antibodies.Conclusions: Lower COVID-19 vaccine humoral response was observed in specific populations compared to controls. A third dose of vaccine in the primary regimen had a positive effect on both percentages of patients who developed anti-Spike IgG antibodies and specific neutralizing antibodies