44 research outputs found
MISE AU POINT D'UNE NOUVELLE STRATEGIE POUR LE DIAGNOSTIC MOLECULAIRE DE LA POLYKYSTOSE RENALE AUTOSOMIQUE DOMINANTE ASSOCIEE A PKD1 (DES NEPHROLOGIE)
No full textAIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
Volume plaquettaire moyen et dysfonction de la fistule artério-veineuse dans une cohorte prospective de patients hémodialysés chroniques
No full textThèse présentée sous la forme d'une" thèse article"Introduction: Arteriovenous fistula (AVF) is the vascular access of 78% of haemodialysis patients in France. AVF dysfunctions such as thrombosis or stenosis are common complications. They are responsible for 30% of hospitalizations of chronic haemodialysis patients. One of the main factors behind these dysfunctions is an abnormality of hyperactive platelet-dependent coagulation during chronic renal failure. The more excitable young platelets are larger. Mean platelet volume (MPV) is a risk marker for major cardiovascular events.Objectives: Prospectively study MPV in our cohort of chronic haemodialysis as predictive marker of AVF dysfunction (occurrence of stenosis and acute thrombosis). We will study the mortality, the occurrence of cardiovascular events and serious haemorrhagic events.Materials and methods: The study included all chronic haemodialysis patients from the Conception Hospital at the CHU of Marseille between June 2014 and June 2016, component 226 patients. The main objective was to observe if there is a difference in the incidence of events on the AVF as dependent of the MPV. The population was divided according to 4 MPV levels determined by MPV quartiles in our cohort. The primary endpoint is a composite element called " AVF event" grouping: AVF acute thrombosis and AVF dysfunction requiring fistulography with endovascular treatment. Statistical analysis was done univarially by a Kaplan-Meier survival model and multivariate by a COX modelResults: 193 patients were included in the study with a median follow-up of 620 days. The median VPM was 10.8 fl [7.8-13.5] and the following quartiles: group 1: VPM ≤ 10fl, group 2: 10.1fl ≤ VPM <10.7fl, group 3: 10.7fl ≤ VPM <11, 5fl, group 4: VPM ≥ 11.5 fl. There was no difference in the characteristics of these 4 groups. There was a higher incidence (p = 0.001) in group 4 with 23 events (59%), 14 (34%) in group 3, 11 (27%) in group 2 and 6 (18%) in group 1. The multivariate analysis shows an independent association between the MPV and the risk of occurrence of an event, the OR is 1.66 [1.24-2.23] p = 0.0007. There was no significant difference in mortality, occurrence of cardiovascular events or serious bleeding events.Conclusion: We have shown in our cohort of chronic haemodialysis that the risk of occurrence of an event on arteriovenous fistula (dysfunction requiring the realization of fistulography or acute thrombosis) is predicted by measuring the MPV. It thus makes it possible to identify the patients at risk of events on the AVF. This population could benefit from enhanced surveillance or anti-aggregating or anticoagulant therapies. Limiting the number of events on the AVF would reduce the occurrence of thrombosis or even loss of vascular access exposing the patient to a vital risk.Introduction : la fistule artérioveineuse (FAV) est la voie d’abord vasculaire de 78% des patients en hémodialyse en France. Les dysfonctions de la FAV à type de thrombose ou de sténose sont des complications fréquentes. Elles sont responsables de 30% des hospitalisations des hémodialysés chroniques. Un des principaux facteurs à l’origine de ces dysfonctions est une anomalie de la coagulation dépendante des plaquettes hyperactives au cours de l’insuffisance rénale chronique. Les plaquettes jeunes plus excitables sont de plus grande taille. Le volume plaquettaire moyen (VPM) est un marqueur de risque d’événements cardiovasculaires majeurs. Objectifs : étudier prospectivement le VPM dans notre cohorte d’hémodialysés chronique comme marqueur prédictif de dysfonction de la FAV (survenue de sténose et de thrombose aiguë). Nous étudierons la mortalité, la survenue d’événements cardio-vasculaires et d’événements hémorragiques graves.Matériels et méthodes : l’étude inclus l’ensemble des patients hémodialysés chronique de l’hôpital de la Conception au CHU de Marseille entre Juin 2014 et Juin 2016, soit 226 patients. L’objectif principal était d’observer s’il existe une différence d’incidence des évènements sur la FAV en fonction du VPM. La population était divisée selon 4 niveau de VPM déterminés selon les quartiles du VPM dans notre cohorte. Le critère de jugement principal est un élément composite dénommé « évènement de FAV » regroupant : thrombose aigue de FAV et dysfonction de FAV ayant nécessité une fistulographie avec traitement endovasculaire. L’analyse statistique a été faite de façon univariée par un modèle de survie Kaplan-Meier et de façon multivariée par un modèle de COXRésultats : 193 patients ont été inclus dans l’étude avec une médiane de suivi de 620 jours. Le VPM moyen était de 10,8 fl [7.8-13.5] et les quartiles suivants : groupe 1 : VPM ≤ 10fl, groupe 2 : 10,1fl ≤ VPM < 10,7fl, groupe 3 : 10,7fl ≤ VPM < 11,5fl, groupe 4 : VPM ≥ 11,5fl. Il n’existait pas de différence concernant les caractéristiques de ces 4 groupes. On note une incidence plus grande (p=0,001) dans le groupe 4 avec 23 évènements (59%), 14 (34%) dans le groupe 3, 11 (27%) dans le groupe 2 et 6 (18%) dans le groupe 1. L’analyse multivariée montre une association indépendante entre le VPM et le risque de survenue d’un événement, l’OR est de 1,66 [1,24-2,23] p=0.0007. Il n’existait pas de différence significative concernant la mortalité, la survenue d’événements cardio-vasculaires ou d’événements hémorragiques graves.Conclusion : nous avons montré dans notre cohorte d’hémodialysés chronique que le risque de survenue d’un évènement sur fistule artérioveineuse (dysfonction nécessitant la réalisation d’une fistulographie ou thrombose aigue) est prédit par la mesure du VPM. Il permet ainsi d’identifier les patients à risque d’évènements sur la FAV. Cette population à risque pourrait bénéficier d’une surveillance renforcée voir de thérapeutiques antiagrégantes ou anticoagulantes. Limiter le nombre d’évènements sur la FAV permettrait de réduire la survenue de thromboses voire de perte de l’accès vasculaire exposant le patient à un risque vital
Tryptophan-Derived Uremic Toxins and Thrombosis in Chronic Kidney Disease
No full textPatients with chronic kidney disease (CKD) display an elevated risk of thrombosis. Thrombosis occurs in cardiovascular events, such as venous thromboembolism, stroke, and acute coronary syndrome, and is a cause of hemodialysis vascular access dysfunction. CKD leads to the accumulation of uremic toxins, which exerts toxic effects on blood and the vessel wall. Some uremic toxins result from tryptophan metabolization in the gut through the indolic and the kynurenine pathways. An increasing number of studies are highlighting the link between such uremic toxins and thrombosis in CKD. In this review, we describe the thrombotic mechanisms induced by tryptophan-derived uremic toxins (TDUT). These mechanisms include an increase in plasma levels of procoagulant factors, induction of platelet hyperactivity, induction of endothelial dysfunction/impairment of endothelial healing, decrease in nitric oxide (NO) bioavailability, and production of procoagulant microparticles. We focus on one important prothrombotic mechanism: The induction of tissue factor (TF), the initiator of the extrinsic pathway of the blood coagulation. This induction occurs via a new pathway, dependent on the transcription factor Aryl hydrocarbon receptor (AhR), the receptor of TDUT in cells. A better understanding of the prothrombotic mechanisms of uremic toxins could help to find novel therapeutic targets to prevent thrombosis in CKD
Enhancing Ammonia Sensor Sensitivity by CuBr Encapsulation in a Mesoporous Host
No full textA resistive room-temperature ammonia sensor has been developed by CuBr impregnation of a mesoporous SiO2 host prepared by the sol–gel process and deposited by dip-coating. The mesoporous sensor performances are compared with those of a single CuBr layer. The CuBr encapsulation in a mesoporous host leads to an impressive sensitivity improvement with sub-ppm detection of ammonia at room temperature. The results open new perspectives for the development of highly sensitive chemical sensors and are of great interest for non-invasive health monitoring
Clinical features and outcomes of ANCA-associated renal vasculitis
No full textTo determine the patterns and outcomes of the pauci-immune vasculitis in the nephrology department at hospital La Conception in Marseille, we conducted a retrospective study including all patients with diagnosis of pauci-immune renal vasculitis between January 1, 2000 and December 31, 2007. Among 33 cases, 25 were diagnosed as Wegener granulomatosis (WG), seven as microscopic polyangitis (MPA) and one as Churg-Strauss syndrome (SCS). The median age of the patients was 57.7 years and the sex-ratio (M/F) was 1.6. The visceral mani-festations included kidneys (100% of patients), lungs (75%), ENT (52% of WG), and nervous system (57% of MPA). The mean serum creatinine at admission was 3.3 mg/dL. Renal biopsies revealed a pauci-immune crescentic gromerulonephritis in 96% of the cases. Two patients with WG received plasmapheresis and seven patients required emergency hemodialysis. Induction therapy comprised cyclophosphamide IV and corticosteroids, while maintenance therapy included azathioprine for the majority of patients. Eighty four percent of the patients experienced complete remission after induction therapy. During maintenance therapy relapses were more frequent among patients with MPA (28%) compared to WG cases (12%). After 35 months of follow-up, eight patients ended on chronic hemodialysis, and five patients died. ANCA associated vasculitis are frequent in our patients. Long-term outcomes are relatively good despite a mortality rate of 15% and 25% of the patients entering dialysis after three years of follow-up
Research and Therapeutic Nihilisms in Chronic Kidney Disease.
No full textInternational audienceWe congratulate Baber et al. (1) for their new analysis of the PROMETHEUS registry. Large real-life registries are critical to confirm the efficacy and safety of new drugs and provide data for key subgroups of patients who are under-represented in clinical trials (CT). Although patients with chronic kidney disease (CKD) compose between 20% and 40% of acute coronary syndromes, they were under-represented in the PLATO (Study of Platelet Inhibition and Patient Outcomes) and TRITON-TIMI 38 (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis in Myocardial Infarction 38) trials. In the present study, Baber et al. (1) investigated the real-life outcome of prasugrel compared with clopidogrel in acute coronary syndromes undergoing percutaneous coronary intervention based on kidney function. They identified a lower use of prasugrel in this high ischemic risk population. This is related to therapeutic nihilism, which is well recognized in patients with CKD. Another key result is the lack of significant difference in outcomes after adjustments between prasugrel and clopidogrel (1). However, it should be acknowledged that this lack of significant difference does not imply a lack of benefit of new P2Y12-ADP receptor antagonists given the limited power of the analysis and the methodology
A new approach for selective and ultrasensitive ammonia sensors by CuBr encapsulation in a mesoporous thin film for potential metabolic acidosis non-invasive monitoring
No full textInternational audienceGe-rich Ge 2 Sb 2 Te 5 (GGST) is considered as one of the best candidates for industrial phase change memory production. GGST memory cells are generally embedded with Si or Ti nitride layers to prevent oxidation, as it leads to an undesired decrease of the GGST crystallization temperature. Furthermore, GGST films are usually doped with elements such as N, C, O, or Bi, aiming to delay GGST crystallization during the fabrication process as well as during memory cell operation. In this work, ultrahigh vacuum thermal desorption spectroscopy (TDS) was performed during isochronal annealing of a N-doped GGST film covered by a 10 nm-thick TiN x layer. Desorption is observed before GGST crystallization, but the comparison between TDS and in situ x-ray diffraction measurements shows that the main desorption peak, observed between 653 K and 703 K, occurs after GGST full crystallization. The most prominent desorbing species are Ar, N 2 , H 2 , and H. These results show that the TiN x polycrystalline layer cannot prevent N atoms from leaving the GGST layer during annealing, suggesting a progressive change of the N-doped GGST chemical composition during thermal annealing and crystallization
Tuberous Sclerosis Complex–Associated Tubulointerstitial Kidney Disease
No full textTuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disease caused by TSC1 or TSC2 mutations, leading to mammalian target of rapamycin (mTOR) overactivation.1 It is characterized by various benign tumors. Renal involvement mainly includes angiomyolipomas (AMLs) or renal cysts. Chronic kidney disease (CKD) in patients with TSC is rare and is usually attributed to nephron reduction related to AML size, ablative therapy, or surgery.2-4 According to various cohorts, the prevalence of stage 2 CKD is 25% and that of stage 3 CKD approximately 7%, with a median age of onset of renal failure in the fourth decade of life.4,S1 Of particular interest, some patients with TSC develop CKD without large AML and/or invasive therapies. We performed a clinicopathologic evaluation of 7 patients with TSC with CKD, providing further insights into a potential new form of TSC-associated tubulointerstitial kidney disease
