Vascularites et exposition à la silice (à propos d'un cas observé chez un prothésiste dentaire)

L'inhalation répétée de silice expose au développement de lésions pulmonaires fibrosantes. Indépendamment de l'atteinte pulmonaire, l'exposition à la silice s'accompagne parfois de perturbations immunologiques, caractérisées par la fréquence des anticorps anti-nucléaires et du facteur rhumatoïde. L'exposition à la silice favorise la survenue de sclérodermie, de polyarthrite rhumatoïde, de lupus érythémateux disséminé et de dermatomyosite et peut être également associée à des néphropathies. L'atteinte rénale correspond le plus souvent à des glomérulonéphrites nécrosantes pauci-immunes associées aux anticorps anti-myélopéroxidase et survient généralement après une exposition prolongée à la silice. Des atteintes systémiques réalisant un tableau de granulomatose de Wegener ou de polyangéite microscopique sont également décrits. La silice, par ses effets immunomodulateurs, sa capacité à induire la lyse des macrophage et l'activation des polynucléaires neutrophiles, favoriserait l'apparition des ANCA et le développement de vascularites. Si l'étiologie des vascularites demeure inconnue dans la majorité des cas, la recherche d'une exposition à un médicament ou à un toxique tel que la silice devrait être systématique. L'association d'une glomérulonéphrite nécrosante et de dépôts extra-membraneux rapportée dans notre observation peut être rapprochée de l'association glomérulonéphrite extra-membraneuse - glomérulonéphrite extra capillaire observée avec la D-pénicillamine suggérant un mécanisme physiopathologique voisin.ROUEN-BU Médecine-Pharmacie (765402102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

À la campagne ou sur la côte, les <i>villae</i> de Chantonnay et de Jard-sur-Mer

International audienc

Preclinical and Clinical Cases of New Absorbable Composite Interference Screws in Osteoarticular Surgery

The objective of this study deals with preclinical and clinical cases of absorbable composite interference screws of next generation in osteoarticular surgery. These implants are made of resorbable polymers PLA either amorphous or semi-cristalline, associated with granules of microporous biphasic calcium phosphate ceramic. A preclinical study was performed on goats in femoral and tibial epiphysis during 4 and 6 months. Histological and histomorphometric results were obtained by micro CT, light and scanning electron microscopy. The comparative statistical in vivo study of the kinetics of resorption and bone regeneration have shown the superiority of the composite compared to control (polymer alone). Thus the presence of Biphasic Calcium Phosphate granules in the composite has a major role for bone regeneration at the expense of the implant (buffering effect and properties of osteoconduction). An observational and functional study involving 10 patients, with a follow-up from 17 to 33 months (mean 25.7), was performed. Data were analyzed according to Good Clinical Practice and International Conference on Harmonisation. Clinical observations have revealed no complications and no serious event was reported; quantitative functional indices confirm the good observational results. The clinical study supports the functionality and performance of this new composite with properties of osteoconduction related to the osteogenicity of microporous biphasic calcium phosphate granules in the field of knee ligament fixation.</jats:p

Self Hardening Macroporous Biphasic Calcium Phosphate Bone Void Filler for Bone Reconstruction; Animal Study and Human Data

Due to the lack of macroporosity in current available Calcium Phosphate cement used in osteoarticular surgery, Micro and Macroporous Biphasic CaP Cement (MCPC™) was developed. The MCPC™ concept was the association of a settable and a fast resorbable matrix and a sieved fraction of microporous biphasic calcium phosphate (BCP) granules, recognized for the high osteoconductive and osteogenic properties. During the resorption of the matrix, a porous structure is created and the osteoconductive effect of the granules promotes the bone ingrowth. A goat preclinical study was realized to evaluate the efficacy of MCPC™ for C3 and C4 vertebral body filling defects during 6 months. Bone remodelling was evidenced demonstrating bone ingrowth at the expense of the cement and surrounding the residual BCP granules. Bone trabeculae were observed coming from the spongious bone to the implant site. Human vertebral body filling cases demonstrated the biocompatibility and the safety of MCPC™ for bone reconstruction. Results of this study demonstrated the importance of special combination of calcium phosphate granules in the MCPC™ to provide macroporosity and scaffolding for newly formed bone.</jats:p

Relative Change of Protidemia Level Predicts Intradialytic Hypotension

Background Hemodialysis patients are at risk of intradialytic hypotension ( IDH ), which is associated with mortality and cardiovascular and neurological events. The use of biomarkers of volemia such as relative change in protidemia and BNP (B‐natriuretic peptide) levels to predict IDH remains unknown. Methods and Results We conducted a prospective observational study, which enrolled 170 chronic hemodialysis patients in a single center from September 2015 to March 2016. BNP and the relative change of protidemia level (Δprotidemia=postdialysis protidemia−predialysis protidemia) were measured monthly over 6 months. A logistic mixed regression model was used to define the best biomarkers that predict the 30‐day risk of IDH . Receiver operating characteristic analysis area under the curve was used to define the cutoff values of Δprotidemia that predict IDH A logistic mixed model reveals that Δprotidemia predicts the 30‐day risk of IDH but not BNP or age; odds ratio=1.12, 95% CI 1.08‐1.17), odds ratio=0.81, 95% CI (0.64; 1.07) and odds ratio =0.015 95% CI (0.99; 1.03), respectively. Adding the ultrafiltration rate did not improve the model. A receiver operating characteristic curve analysis showed that Δprotidemia of 10 g/L allowed for discrimination of the patients with IDH (area under the curve= 0.67; 95% CI 0.62‐0.72, P &lt;0.05). There was an increase in area under the curve to 0.71 (95% CI 0.63‐0.76) in a subgroup of hemodialysis with BNP &lt;300 ng/L, for a cutoff value of 11 g/L, especially for the nondiabetic patients. Conclusions Relative change in protidemia level (Δprotidemia) outperforms BNP and ultrafiltration rate as a predictor for 30‐day risk of IDH . These results should be confirmed by a prospective study. </jats:sec

A mathematical model to predict BNP levels in hemodialysis patients

International audienceAim: Clinical interpretation of B-Type Natriuretic Peptide (BNP) levels in hemodialysis patients (HD) for fluid management remains elusive.Method: We conducted a retrospective observational monocentric study. We built a mathematical model to predict BNP levels, using multiple linear regressions. Fifteen clinical/biological associated with BNP variation were selected. A first cohort of 150 prevalent HD (from September 2015 to march 2016) was used to build several models. Thebest model proposed was internally validated in an independent cohort of 62 incidents HD (from March 2016 to September 2017).Results: In cohort 1, mean BNP Level was 630±717 ng/ml. Cardiac disease (CD = Stable Coronary Artery Disease and/or Atrial Fibrillation) was present in 45% of patient. The final model includes: Age, systolic Blood Pressure (sBP), Albumin, CD, Normo-hydrated Weight (NHW) and the Fluid Overload (FO) assessed by bio-impedancemetry. The correlationbetween the measured and the predicted log-BNP was 0.567 and 0.543 in cohort-1 and 2 respectively. Age (β=3.175e-2, p<0.00), CD (β=5.243e-1, p<0.001) and FO (β=1.227e-1, p<0.001) contribute the most significantly to the BNP level, respectively, but within a certain range. We observed a logistic relationship between BNP and age between 30 to 60 years, after which this relationship was lost. BNP level was inversely correlated with NHW independently of CD. Finally, our model allows us to predict the BNP level according to the FO.Conclusion: We developed a mathematical model capable of predicting the BNP level in HD. Our results show the complex contribution of age, CD and FO on BNP level