Banc de test pour stent

L'invention concerne un banc test pour stents, caractérisé en ce qu'il comprend une pompe (2) non volumétrique dont l'entrée est raccordée à un réservoir (4) de liquide sanguin ouvert et dont la sortie est reliée à une canalisation (6) d'alimentation d'au moins une éprouvette (8), formée d'un tronçon artériel (10) équipé d'un stent et une canalisation de by-pass (13) équipée d'une restriction (14) de section réglable, l'éprouvette étant reliée à un collecteur (12) de retour du fluide au réservoir (4), les moyens (11) de connexion de l'éprouvette au circuit étant démontables, ce collecteur (12) étant équipé d'un régulateur (17) de pression et un capteur de débit (16) à la sortie de l'éprouvette, la canalisation d'alimentation (6) comportant un capteur de pression à la sortie de la pompe (1), la commande de la pompe étant assurée par une électronique (3) de commande de l'alimentation électrique de son moteur (2) apte à reproduire les phases systoliques et diastoliques du cycle cardiaque, lesdits capteurs (15,16) étant reliés à une carte d'acquisition de données de manière à surveiller le fonctionnement de la pompe, l'éprouvette étant logée dans un milieu nutritif (18) pour le tissu artériel, le réservoir ouvert (4) étant adapté à une oxygénation du liquide sanguin et l'ensemble du circuit hydraulique étant logé dans une enceinte (21) à température régulée

Image fusion performed with noncontrast computed tomography scans during endovascular aneurysm repair

We report two endovascular aneurysm repair procedures achieved under image fusion guidance accomplished with noncontrast injected preoperative computed tomography scans. Such use of this advanced imaging application reduces contrast media injection volume (respectively, 27 and 24 mL throughout the patients' hospital course). No changes in creatinine clearance occurred after the procedures. Contrast-enhanced ultrasound imaging confirmed technical success in both cases

Development and biological evaluation of Iinkjet printed drug coatings on intravascular stent

Inkjet–printing technology was used to apply biodegradable and biocompatible polymeric coatings of poly(D, L lactide) with the antiproliferative drugs simvastatin (SMV) and paclitaxel (PCX) on coronary metal stents. A piezoelectric dispenser applied coating patterns of very fine droplets (300 xL) and ink jetting was optimized to develop uniform, accurate and reproducible coatings of high yields on the stent strut. The drug loaded polymeric coatings were assed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and transition thermal microscopy (TTM) where a phase separation was observed for SMV/PLA layers while PCX showed a uniform distribution within the polymer layers. Cytocompatibility studies of PLA coatings showed excellent cell adhesion with no decrease of cell viability and proliferation. In vivo stent implantation studies showed significant intra stent restenosis (ISR) for PXC/PLA and PLA plain coatings similar to marketed Presillion (bare metal) and Cypher (drug eluting) stents. The investigation of several cytokine levels after seven days of stent deployment showed no inflammatory response and hence no in vivo cytotoxicity related to PLA coatings. Inkjet printing can be employed as a robust coating technology for the development of drug eluting stents compared to the current conventional approaches

Maternally supplied S-acyl-transferase is required for crystalloid organelle formation and transmission of the malaria parasite.

Transmission of the malaria parasite from the mammalian host to the mosquito vector requires the formation of adequately adapted parasite forms and stage-specific organelles. Here we show that formation of the crystalloid-a unique and short-lived organelle of the Plasmodium ookinete and oocyst stage required for sporogony-is dependent on the precisely timed expression of the S-acyl-transferase DHHC10. DHHC10, translationally repressed in female Plasmodium berghei gametocytes, is activated translationally during ookinete formation, where the protein is essential for the formation of the crystalloid, the correct targeting of crystalloid-resident protein LAP2, and malaria parasite transmission

A New Hemodynamic Ex Vivo Model for Medical Devices Assessment

Introduction: In stent restenosis (ISR) remains a major public health concern with an increased morbidity, mortality and health-related costs. Drug-eluting stents (DES) have reduced ISR, but are associated with healing-related issues or hypersensitivity reactions, leading to an increased risk of late acute stent thrombosis. Evaluations of new DES are based on animal models or in vitro release systems which show several limitations. The role of flow and shear stress on endothelial cell and ISR has also been emphasized. The aim of this work was to design and first evaluate an original bioreactor, reproducing ex vivo hemodynamic and biological conditions similar to human conditions, to further evaluate new DES. Methods & Results: This bioreactor was designed to study up to 6 stented arteries connected in bypass, immersed in a culture box, in which circulated a physiological systolo-diastolic resistive flow. Two centrifugal pumps drove the flow. The principal pump generated pulsating flows by modulation of rotation velocity, and the second pump worked at constant rotation velocity, ensuring the counter pressure levels and backflows. The flow rate, the velocity profile, the arterial pressure and the resistance of the flow were adjustable. The bioreactor was placed in an incubator to reproduce a biological environment. A first experience of feasibility was realized over a period of 24 days. Three rat aortic thoracic arteries were placed into the bioreactor, immersed in cell culture medium change every 3 days, and with a circulating systole diastolic flux circulating among the entire experimentation. There was no infection, no leak. At the end of experimentation, a morphometric analysis was performed confirming the viability of the arteries. Conclusion: We design and patent an original hemodynamic ex vivo model to further study new DES and ISR. We will next validate this ex vivo model of ISR reproducing this experimentation with stented arteries. Once validated, this bioreactor will allow characterization of the velocity field and drug transfers within a stented artery with new functionalized DES, with experimental means not available in vivo. Another main point will be the reduction of animal experimentation, and the availability of first results of new DES in human tissues (human infra popliteal or coronary arteries collected during human donation)

Generation of a genetically modified chimeric plasmodium falciparum parasite expressing plasmodium vivax circumsporozoite protein for malaria vaccine development

Copyright © 2020 Miyazaki, Marin-Mogollon, Imai, Mendes, van der Laak, Sturm, Geurten, Miyazaki, Chevalley-Maurel, Ramesar, Kolli, Kroeze, van Schuijlenburg, Salman, Wilder, Reyes-Sandoval, Dechering, Prudencio, Janse, Khan and ̂ Franke-Fayard. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Chimeric rodent malaria parasites with the endogenous circumsporozoite protein (csp) gene replaced with csp from the human parasites Plasmodium falciparum (Pf) and P. vivax (Pv) are used in preclinical evaluation of CSP vaccines. Chimeric rodent parasites expressing PfCSP have also been assessed as whole sporozoite (WSP) vaccines. Comparable chimeric P. falciparum parasites expressing CSP of P. vivax could be used both for clinical evaluation of vaccines targeting PvCSP in controlled human P. falciparum infections and in WSP vaccines targeting P. vivax and P. falciparum. We generated chimeric P. falciparum parasites expressing both PfCSP and PvCSP. These Pf-PvCSP parasites produced sporozoite comparable to wild type P. falciparum parasites and expressed PfCSP and PvCSP on the sporozoite surface. Pf-PvCSP sporozoites infected human hepatocytes and induced antibodies to the repeats of both PfCSP and PvCSP after immunization of mice. These results support the use of Pf-PvCSP sporozoites in studies optimizing vaccines targeting PvCSP.CM-M was, in part, supported by Colciencias Ph.D. fellowship (Call 568 from 2012 Resolution 01218 Bogotá, Colombia). TI was, in part, supported by Uehara Memorial Foundation grant. Work performed at IMM was supported by Fundação para a Ciência e Tecnologia (FCT-Portugal)’s grants PTDC/BBB-BMD/2695/2014 and PTDC-SAU-INF-29550-2017. AR-S is supported by the MRC-DPFS grant MR/N019008/1.info:eu-repo/semantics/publishedVersio

Creation and preclinical evaluation of genetically attenuated malaria parasites arresting growth late in the liver.

Whole-sporozoite (WSp) malaria vaccines induce protective immune responses in animal malaria models and in humans. A recent clinical trial with a WSp vaccine comprising genetically attenuated parasites (GAP) which arrest growth early in the liver (PfSPZ-GA1), showed that GAPs can be safely administered to humans and immunogenicity is comparable to radiation-attenuated PfSPZ Vaccine. GAPs that arrest late in the liver stage (LA-GAP) have potential for increased potency as shown in rodent malaria models. Here we describe the generation of four putative P. falciparum LA-GAPs, generated by CRISPR/Cas9-mediated gene deletion. One out of four gene-deletion mutants produced sporozoites in sufficient numbers for further preclinical evaluation. This mutant, PfΔmei2, lacking the mei2-like RNA gene, showed late liver growth arrest in human liver-chimeric mice with human erythrocytes, absence of unwanted genetic alterations and sensitivity to antimalarial drugs. These features of PfΔmei2 make it a promising vaccine candidate, supporting further clinical evaluation. PfΔmei2 (GA2) has passed regulatory approval for safety and efficacy testing in humans based on the findings reported in this study

Replication of Plasmodium in reticulocytes can occur without hemozoin formation, resulting in chloroquine resistance

Most studies on malaria-parasite digestion of hemoglobin (Hb) have been performed using P. falciparum maintained in mature erythrocytes, in vitro. In this study, we examine Plasmodium Hb degradation in vivo in mice, using the parasite P. berghei, and show that it is possible to create mutant parasites lacking enzymes involved in the initial steps of Hb proteolysis. These mutants only complete development in reticulocytes and mature into both schizonts and gametocytes. Hb degradation is severely impaired and large amounts of undigested Hb remains in the reticulocyte cytoplasm and in vesicles in the parasite. The mutants produce little or no hemozoin (Hz), the detoxification by-product of Hb degradation. Further, they are resistant to chloroquine, an antimalarial drug that interferes with Hz formation, but their sensitivity to artesunate, also thought to be dependent on Hb degradation, is retained. Survival in reticulocytes with reduced or absent Hb digestion may imply a novel mechanism of drug resistance. These findings have implications for drug development against human-malaria parasites, such as P. vivax and P. ovale, which develop inside reticulocytes

The sac evolution imaging follow-up after endovascular aortic repair:An international expert opinion-based Delphi consensus study

Objective: Management of follow-up protocols after endovascular aortic repair (EVAR) varies significantly between centers and is not standardized according to sac regression. By designing an international expert-based Delphi consensus, the study aimed to create recommendations on follow-up after EVAR according to sac evolution. Methods: Eight facilitators created appropriate statements regarding the study topic that were voted, using a 4-point Likert scale, by a selected panel of international experts using a three-round modified Delphi consensus process. Based on the experts' responses, only those statements reaching a grade A (full agreement ≥75%) or B (overall agreement ≥80% and full disagreement &lt;5%) were included in the final document. Results: One-hundred and seventy-four participants were included in the final analysis, and each voted the initial 29 statements related to the definition of sac regression (Q1-Q9), EVAR follow-up (Q10-Q14), and the assessment and role of sac regression during follow-up (Q15-Q29). At the end of the process, 2 statements (6.9%) were rejected, 9 statements (31%) received a grade B consensus strength, and 18 (62.1%) reached a grade A consensus strength. Of 27 final statements, 15 (55.6%) were classified as grade I, whereas 12 (44.4%) were classified as grade II. Experts agreed that sac regression should be considered an important indicator of EVAR success and always be assessed during follow-up after EVAR. Conclusions: Based on the elevated strength and high consistency of this international expert-based Delphi consensus, most of the statements might guide the current clinical management of follow-up after EVAR according to the sac regression. Future studies are needed to clarify debated issues.</p