Automatisation des mesures cinétiques en dynamique dans le cas de la réaction catalytique gaz-solide d'oxydation ménagée du propène

We have developed an apparatus to study the kinetics of the catalytic reaction of propylene soft oxdation in a flowing system. Following a preestablished program, the apparatus is able to execute a series of measurements without the need for operator interference. In this way we have collected a significantly increased volume of experimental values and we can now envisage a statistical treatment of these values. This development has led us to co nceive of and realize several new types of apparatus.Nous avons réalisé un appareil pour l'étude cinétique en dynamique de la réaction catalytique d'oxydation ménagée du propène, pouvant effectuer des séries de mesures sans l'intervention d'un opérateur et suivant un programme préétabli. Le nombre de valeurs expérimentales obtenues s'en trouve considérablement accru, ce qui rend plus sûre l'interprétation des résultats et permet d'envisager un dépouillement statistique. Cette réalisation nous a conduit à concevoir et mettre au point un certain nombre de systèmes originaux que nous décrivons dans ce texte

Contrast-Enhanced and Time-of-Flight MRA at 3T Compared with DSA for the Follow-Up of Intracranial Aneurysms Treated with the WEB Device

International audienceBACKGROUND AND PURPOSE:Imaging follow-up at 3T of intracranial aneurysms treated with the WEB Device has not been evaluated yet. Our aim was to assess the diagnostic accuracy of 3D-time-of-flight MRA and contrast-enhanced MRA at 3T against DSA, as the criterion standard, for the follow-up of aneurysms treated with the Woven EndoBridge (WEB) system.MATERIALS AND METHODS:From June 2011 to December 2014, patients treated with the WEB in our institution, then followed for ≥6 months after treatment by MRA at 3T (3D-TOF-MRA and contrast-enhanced MRA) and DSA within 48 hours were included. Aneurysm occlusion was assessed with a simplified 2-grade scale (adequate occlusion [total occlusion + neck remnant] versus aneurysm remnant). Interobserver and intermodality agreement was evaluated by calculating the linear weighted κ. MRA test characteristics and predictive values were calculated from a 2 × 2 contingency table, by using DSA data as the standard of reference.RESULTS:Twenty-six patients with 26 WEB-treated aneurysms were included. The interobserver reproducibility was good with DSA (κ = 0.71) and contrast-enhanced-MRA (κ = 0.65) compared with moderate with 3D-TOF-MRA (κ = 0.47). Intermodality agreement with DSA was fair with both contrast-enhanced MRA (κ = 0.36) and 3D-TOF-MRA (κ = 0.36) for the evaluation of total occlusion. For aneurysm remnant detection, the prevalence was low (15%), on the basis of DSA, and both MRA techniques showed low sensitivity (25%), high specificity (100%), very good positive predictive value (100%), and very good negative predictive value (88%).CONCLUSIONS:Despite acceptable interobserver reproducibility and predictive values, the low sensitivity of contrast-enhanced MRA and 3D-TOF-MRA for aneurysm remnant detection suggests that MRA is a useful screening procedure for WEB-treated aneurysms, but similar to stents and flow diverters, DSA remains the criterion standard for follow-up

Fluconazole in hypercalciuric patients with increased 1,25(OH)(2)D levels: the prospective, randomized, placebo-controlled, double-blind FLUCOLITH trial

International audienceBACKGROUND: Hypercalciuria is one of the most frequent metabolic disorders associated with nephrolithiasis and/or nephrocalcinosis possibly leading to chronic kidney disease (CKD) and bone complications in adults. Orphan diseases with different underlying primary pathophysiology share inappropriately increased 1,25(OH)(2)D levels and hypercalciuria, e.g., hypersensitivity to vitamin D and renal phosphate wasting. Their management is challenging, typically based on hyperhydration and dietary advice. The antifungal azoles are known to inhibit the 1α-hydroxylase and therefore decrease 1,25(OH)(2)D levels; they are commonly used, with well described pharmacokinetic and tolerability data. Fluconazole has been successfully reported to reduce calciuria in patients with CYP24A1 or SLC34A3 mutations, with no safety warnings. Thus, based on these case reports, we hypothesize that fluconazole is effective to decrease and normalize calciuria in patients with hypercalciuria and increased 1,25(OH)(2)D levels. METHODS: The FLUCOLITH trial is a prospective, interventional, randomized in parallel groups (1:1), placebo-controlled, double-blind trial. A total of 60 patients (10-60 years) with nephrolithiasis and/or nephrocalcinosis history, hypercalciuria (\textgreater 0.1 mmol/kg/day), increased 1,25(OH)(2)D levels (\textgreater 150 pmol/L), and 25-OH-D levels \textgreater20 nmol/L will be included. Inclusions will be performed only from mid-September to the beginning of February to avoid bias due to sunlight-induced vitamin D synthesis. The primary endpoint will be the proportion of patients with normalization of 24-h calciuria between baseline and 16 weeks, or with a relative decrease of at least 30% of 24-h calciuria in patients who still display at W16 a 24-h hypercalciuria. DISCUSSION: The current challenge is to propose an efficient treatment to patients with hypercalciuria and increased 1,25(OH)(2)D levels in order to prevent later complications and notably CKD that can ultimately lead to end-stage renal disease. Based on improvement of knowledge in phosphate/calcium metabolism, pathophysiology and genetics, the "off-label" use of fluconazole was recently reported to be useful in hypercalciuric patients with increased 1,25(OH)(2)D levels. Thus, the FLUCOLITH study is a unique opportunity to develop a new indication of a well-known and not expensive drug in orphan renal diseases, the ultimate objective being the secondary prevention of CKD worsening in these patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT04495608 . Registered on July 23, 2020