Comparison of methods to determine extraction efficiencies of Ra isotopes and 227Ac from large volume seawater samples

International audienceRadium isotopes, other than 226Ra, and 227Ac are typically present at low activities in the open ocean. The analysis of these isotopes thus requires the collection of large volumes of seawater and high sensitivity, low background instruments. To obtain the required large volumes (hundreds to thousands of liters), these radionuclides are typically preconcentrated on cartridge-style filters impregnated with MnO2 (Mn-cartridges) deployed on in-situ pumps. This technique, however, requires the determination of the extraction efficiency of the Mn-cartridges for the radionuclides of interest. For Ra isotopes, we used two methods to estimate the extraction efficiency of these Mn-cartridges at two stations on the South-West Indian Ridge in the Southern Ocean (GEOTRACES GS02). Method (1) compares the 226Ra activities recovered on the Mn-cartridges versus the activities determined in Mn-fibers, through which seawater was passed at a flow rate < 1 L min−1 to quantitatively sorb Ra (Mn-fiber method) while method (2) combines the 226Ra activities determined from two Mn-cartridges placed in series on in-situ pumps (A-B method). The second method is also applied to determine the 227Ac extraction efficiency. We find a relatively wide-range of Ra and 227Ac extraction efficiencies across the dataset (from 44.8% to 99.6% for Ra, and from 23.7% to 77.5% for 227Ac). Overall, the yield of 227Ac extraction is lower than that of Ra (mean value of 49.3 ± 19.0% for 227Ac, n = 10, mean value of 79.2 ± 10.3% for Ra, n = 13, using the Mn-fiber method; and a mean value of 63.9 ± 12.5%, n = 11 using the A-B method). Our dataset suggests that the Ra extraction efficiencies using either the A-B method or the Mn-fiber method are in relatively good agreement. Consequently, the 223Raex, 224Raex and 228Ra activities determined from the Mn-cartridges by applying the two Ra extraction yields are similar. We also show that the 227Ac extraction efficiency can be estimated from the Ra extraction efficiency allowing the use of a single Mn-cartridge. Finally, we recommend to determine the Ra and 227Ac extraction efficiencies in each individual Mn-cartridge, rather than applying a single extraction efficiency to all the Mn-cartridges, since a significant variability in the extraction efficiencies was observed between the different Mn-cartridges

Use of 223 Ra and 224 Ra as chronometers to estimate the residence time of Amazon waters on the Brazilian continental shelf

International audienc

Investigation of hydrothermal activity in the South West Indian ridge region using Ra isotopes and ²²⁷Ac as tracers

International audienc

Cannabis Use Is Inversely Associated with Overweight and Obesity in Hepatitis B Virus-Infected Patients (ANRS CO22 Hepather Cohort)

International audienceBackground: Chronic hepatitis B virus (HBV) infection may evolve into cirrhosis and hepatocellular carcinoma, and this progression may be accelerated by specific risk factors, including overweight and obesity. Although evidence for a protective effect of cannabis use on elevated body weight has been found for other populations, no data are available for HBV-infected patients.Aims: We aimed to identify risk factors (including cannabis use) for overweight and obesity in patients with HBV chronic infection.Methods: Using baseline data from the French ANRS CO22 Hepather cohort, we performed two separate analyses, one using “central obesity” (based on waist circumference) and the other “overweight” and “obesity” (based on body mass index) as outcomes. Logistic and multinomial regressions were used to model central obesity and overweight/obesity, respectively.Results: Among the 3706 patients in the study population, 50.8% had central obesity, 34.7% overweight, and 14.4% obesity. After multivariable adjustment, current cannabis use was associated with a 59% lower risk of central obesity compared with no lifetime use (adjusted odds ratio [95% CI]: 0.41 [0.24 to 0.70]). It was also associated with a 54% and 84% lower risk of overweight (adjusted relative risk ratio [95% CI]: 0.46 [0.27 to 0.76]) and obesity (0.16 [0.04 to 0.67]), respectively.Conclusions: Cannabis use was associated with lower risks of overweight and obesity in patients with HBV chronic infection. Future studies should test whether these potential benefits of cannabis and cannabinoid use translate into reduced liver disease progression in this high-risk population

Cannabis Use Is Inversely Associated with Overweight and Obesity in Hepatitis B Virus-Infected Patients (ANRS CO22 Hepather Cohort)

International audienc

Impact of the first wave of COVID-19 epidemy on the surgical management of sigmoid diverticular disease in France: National French retrospective study

International audienceObjective: To analyze the surgical management of sigmoid diverticular disease (SDD) before, during, and after the first containment rules (CR) for the first wave of COVID-19.Methods: From the French Surgical Association multicenter series, this study included all patients operated on between January 2018 and September 2021. Three groups were compared: A (before CR period: 01/01/18-03/16/20), B (CR period: 03/17/20-05/03/20), and C (post CR period: 05/04/20-09/30/21).Results: A total of 1965 patients (A n = 1517, B n = 52, C n = 396) were included. The A group had significantly more previous SDD compared to the two other groups (p = 0.007), especially complicated (p = 0.0004). The rate of peritonitis was significantly higher in the B (46.1%) and C (38.4%) groups compared to the A group (31.7%) (p = 0.034 and p = 0.014). As regards surgical treatment, Hartmann's procedure was more often performed in the B group (44.2%, vs A 25.5% and C 26.8%, p = 0.01). Mortality at 90 days was significantly higher in the B group (9.6%, vs A 4% and C 6.3%, p = 0.034). This difference was also significant between the A and B groups (p = 0.048), as well as between the A and C groups (p = 0.05). There was no significant difference between the three groups in terms of postoperative morbidity.Conclusion: This study shows that the management of SDD was impacted by COVID-19 at CR, but also after and until September 2021, both on the initial clinical presentation and on postoperative mortality

Cannabis use as a factor of lower corpulence in hepatitis C-infected patients: results from the ANRS CO22 Hepather cohort

International audienceBackground: Patients with chronic hepatitis C virus (HCV) infection are at greater risk of developing metabolic disorders. Obesity is a major risk factor for these disorders, and therefore, managing body weight is crucial. Cannabis use, which is common in these patients, has been associated with lower corpulence in various populations. However, this relationship has not yet been studied in persons with chronic HCV infection.Methods: Using baseline data from the French ANRS CO22 Hepather cohort, we used binary logistic and multinomial logistic regression models to test for an inverse relationship between cannabis use (former/current) and (i) central obesity (i.e., large waist circumference) and (ii) overweight and obesity (i.e., elevated body mass index (BMI)) in patients from the cohort who had chronic HCV infection. We also tested for relationships between cannabis use and both waist circumference and BMI as continuous variables, using linear regression models.Results: Among the 6348 participants in the study population, 55% had central obesity, 13.7% had obesity according to their BMI, and 12.4% were current cannabis users. After multivariable adjustment, current cannabis use was associated with lower risk of central obesity (adjusted odds ratio, aOR [95% confidence interval, CI]: 0.45 [0.37-0.55]), BMI-based obesity (adjusted relative risk ratio (aRRR) [95% CI]: 0.27 [0.19-0.39]), and overweight (aRRR [95% CI]: 0.47 [0.38-0.59]). This was also true for former use, but to a lesser extent. Former and current cannabis use were inversely associated with waist circumference and BMI.Conclusions: We found that former and, to a greater extent, current cannabis use were consistently associated with smaller waist circumference, lower BMI, and lower risks of overweight, obesity, and central obesity in patients with chronic HCV infection. Longitudinal studies are needed to confirm these relationships and to assess the effect of cannabis use on corpulence and liver outcomes after HCV cure.Trial registration: ClinicalTrials.gov identifier: NCT01953458

Successful Thrombectomy Improves Functional Outcome in Tandem Occlusions with a Large Ischemic Core

International audienceBackground: Emergent stenting in tandem occlusions and mechanical thrombectomy (MT) of acute ischemic stroke related to large vessel occlusion (LVO-AIS) with a large core are tested independently. We aim to assess the impact of reperfusion with MT in patients with LVO-AIS with a large core and a tandem occlusion and to compare the safety of reperfusion between large core with tandem and nontandem occlusions in current practice. Methods: We analyzed data of all consecutive patients included in the prospective Endovascular Treatment in Ischemic Stroke Registry in France between January 2015 and March 2023 who presented with a pretreatment ASPECTS (Alberta Stroke Program Early CT Score) of 0–5 and angiographically proven tandem occlusion. The primary end point was a favorable outcome defined by a modified Rankin Scale (mRS) score of 0–3 at 90 days. Results: Among 262 included patients with a tandem occlusion and ASPECTS 0–5, 203 patients (77.5%) had a successful reperfusion (modified Thrombolysis in Cerebral Infarction grade 2b-3). Reperfused patients had a favorable shift in the overall mRS score distribution (adjusted odds ratio [aOR], 1.57 [1.22–2.03]; P < 0.001), higher rates of mRS score 0–3 (aOR, 7.03 [2.60–19.01]; P < 0.001) and mRS score 0–2 at 90 days (aOR, 3.85 [1.39–10.68]; P = 0.009) compared with nonreperfused. There was a trend between the occurrence of successful reperfusion and a decreased rate of symptomatic intracranial hemorrhage (aOR, 0.5 [0.22–1.13]; P = 0.096). Similar safety outcomes were observed after large core reperfusion in tandem and nontandem occlusions. Conclusions: Successful reperfusion was associated with a higher rate of favorable outcome in large core LVO-AIS with a tandem occlusion, with a safety profile similar to nontandem occlusion