42 research outputs found
Tacrolimus pharmacodynamics and pharmacogenetics along the calcineurin pathway in human lymphocytes.
BACKGROUND:
Although therapeutic drug monitoring has improved the clinical use of immunosuppressive drugs, there is still interpatient variability in efficacy and toxicity that pharmacodynamic monitoring may help to reduce. To select the best biomarkers of tacrolimus pharmacodynamics, we explored the strength and variability of signal transduction and the influence of polymorphisms along the calcineurin pathway.
METHODS:
Peripheral blood mononuclear cells from 35 healthy volunteers were incubated with tacrolimus (0.1-50 ng/mL) and stimulated ex vivo. Inhibition of NFAT1 (nuclear factor of activated T cells 1) translocation to the nucleus and intracellular expression of interleukin-2 in CD4(+) and CD8(+) T cells and the surface activation marker CD25 in CD3(+) cells were measured by flow cytometry. We sequenced the promoter regions of immunophilins and calcineurin subunits and characterized selected single nucleotide polymorphisms in the genes of the calcineurin pathway with allelic discrimination assays.
RESULTS:
All responses closely fitted an I/Imax sigmoid model. Large interindividual variability (n = 30) in I0 and IC50 was found for all biomarkers. Moreover, strong and statistically significant associations were found between tacrolimus pharmacodynamic parameters and polymorphisms in the genes coding cyclophilin A, the calcineurin catalytic subunit α isoenzyme, and CD25.
CONCLUSIONS:
This study demonstrates the consistency and large interindividual variability of signal transduction along the calcineurin pathway, as well as the strong influence of pharmacogenetic polymorphisms in the calcineurin cascade on both the physiological activity of this route and tacrolimus pharmacodynamics.Agencia Nacional de InvestigaciĂłn e InnovaciĂłnUnidda de BiologĂa Molecular, Facultad de QuĂmica, UdelarService de CoopĂ©ration SientĂfique et dÂŽAction Culturelle de lÂŽAmbassade de France en UruguayU1248 INSERM, IPPRITT (Individual Profiling and Preventions of Risks with Immunosuppressive Therapies and Transplantation) UniversitĂ© de Limoges, Franc
LES DĂTERMINANTS DE LA PERFORMANCE FINANCIĂRE DES PETITES ENTREPRISES CAMEROUNAISES
The global censuses of Cameroonian companies that took place in 2009 and 2016 show a mortality rate of 36% of companies over this period. This situation mostly concerns VSEs and SEs which, paradoxically, represent 98.50% of economic activities nationwide. This paper aims to characterize the explanatory factors of Sesâ financial performance in view to enable them best manage their financial performance in a sustainable manner. On a final sample of 489 companies, we perform longitudinal analyses and PLS modeling to simultaneously highlight the internal and external determinants of financial performance. Data analyses results depict a strong dominance of managers and accountants profiles, social climate, management costs and the level of debt, over customerâs satisfaction, competitiveness and fiscal policy. Thus, beyond the indicators linked to managers and accountants, cost control and continuous customer satisfaction guarantee the stability and sustainability of the financial performance of SEs
Cellular basis of urothelial squamous metaplasia: roles of lineage heterogeneity and cell replacement
Although the epithelial lining of much of the mammalian urinary tract is known simply as the urothelium, this epithelium can be divided into at least three lineages of renal pelvis/ureter, bladder/trigone, and proximal urethra based on their embryonic origin, uroplakin content, keratin expression pattern, in vitro growth potential, and propensity to keratinize during vitamin A deficiency. Moreover, these cells remain phenotypically distinct even after they have been serially passaged under identical culture conditions, thus ruling out local mesenchymal influence as the sole cause of their in vivo differences. During vitamin A deficiency, mouse urothelium form multiple keratinized foci in proximal urethra probably originating from scattered K14-positive basal cells, and the keratinized epithelium expands horizontally to replace the surrounding normal urothelium. These data suggest that the urothelium consists of multiple cell lineages, that trigone urothelium is closely related to the urothelium covering the rest of the bladder, and that lineage heterogeneity coupled with cell migration/replacement form the cellular basis for urothelial squamous metaplasia
La Roque-Gageac â La grotte Maldidier
Les opĂ©rations de terrain menĂ©es depuis 2012 dans la grotte Maldidier, petite cavitĂ© qui surplombe la vallĂ©e de la Dordogne, ont pour objectif de caractĂ©riser dans le temps et lâespace, les occupations par les Hommes et les Carnivores au dĂ©but du PalĂ©olithique rĂ©cent. En 2015, les opĂ©rations de fouille se sont concentrĂ©es sur trois zones de la cavitĂ© (entrĂ©e, milieu de couloir et fond de la cavitĂ©). Le matĂ©riel recueilli est composĂ© de nombreux restes de faune, dâindustrie lithique, dâĂ©lĂ©ment..
Recent Laborian of the Peyrazet cave-rock shelter (Creysse, Lot, France). New data for the end of Lateglacial in Quercy
DĂ©couverte en 1990, la grotte-abri de Peyrazet (Creysse, Lot, France) se situe dans le Haut-Quercy en bordure du causse de Martel, Ă quelques centaines de mĂštres du cours actuel de la Dordogne. Les fouilles menĂ©es depuis 2008 livrent une archĂ©osĂ©quence du Tardiglaciaire qui permet de combler certaines lacunes documentaires rĂ©gionales et plus largement du Sud-Ouest de la France. Au MagdalĂ©nien supĂ©rieur succĂšde un niveau ayant donnĂ© des indices dâun Azilien sensu lato stratigraphiquement sĂ©parĂ© du Laborien, ensemble supĂ©rieur qui fait lâobjet de cet article. Jusquâalors ce technocomplexe de la fin du PlĂ©istocĂšne et des dĂ©buts de lâHolocĂšne demeurait mal connu dans la rĂ©gion. En effet, seuls des travaux anciens menĂ©s dans deux gisements permettaient de noter sa prĂ©sence en Quercy. La dĂ©couverte dâun ensemble laborien rĂ©cent (ou Ăpilaborien) Ă Peyrazet est lâoccasion de conduire une Ă©tude collective des divers vestiges dans un cadre archĂ©ostratigraphique mieux maĂźtrisĂ©. Lâanalyse gĂ©oarchĂ©ologique met en Ă©vidence lâaction conjointe du ruissellement et de lâĂ©boulisation comme principaux responsables de la mise en place des dĂ©pĂŽts. Dans la partie S-O du site, un lithofaciĂšs de remaniement indique une bioturbation importante en lien avec le creusement de terriers. Bien que leur origine ne soit pas liĂ©e aux activitĂ©s humaines, les rongeurs, les oiseaux, les poissons et les mĂ©somammifĂšres (exceptĂ© le liĂšvre) apportent des donnĂ©es concernant lâenvironnement des chasseurs-cueilleurs. La grande faune est dominĂ©e par le cerf dont les carcasses pourraient avoir Ă©tĂ© introduites incomplĂštes sur le site puis traitĂ©es pour en extraire la viande et la moelle. Nous avons bĂ©nĂ©ficiĂ© dâune analyse fonctionnelle croisĂ©e Ă lâĂ©tude typo-technologique des vestiges lithiques composĂ©s pour lâessentiel de silex locaux et rĂ©gionaux. Ce double regard a permis de mettre en Ă©vidence une diversitĂ© dâactivitĂ©s mise en Ćuvre dans la cavitĂ©. Une piĂšce dâocre rouge, quelques vestiges dâindustrie osseuse et des Ă©lĂ©ments de parure participent Ă©galement Ă la description dâune large gamme de tĂąches effectuĂ©es lors dâun sĂ©jour prolongĂ© ou de plusieurs occupations successives. La comparaison des pointes de chasse microlithiques avec dâautres gisements sur une vaste Ă©chelle gĂ©ographique conduit Ă discuter lâattribution de cet ensemble supĂ©rieur Ă diffĂ©rentes phases du Laborien. LâhypothĂšse dâun Laborien rĂ©cent (ou Ăpilaborien) conduit Ă rĂ©flĂ©chir Ă une perduration de morphotypes ancestraux parallĂšlement Ă de nouveaux types dâarmatures, observation dĂ©jĂ rĂ©alisĂ©e notamment Ă La Borie del Rey dans le Haut-Agenais mais qui demande encore des prĂ©cisions et de nouvelles dĂ©couvertes.Discovered in 1990, Peyrazet cave-rock shelter (Creysse, Lot) lies in the Haut-Quercy region at the limits of the Martel limestone plateau, several hundred meters from the current Dordogne River valley. Excavations begun in 2008 produced a Late Glacial archaeo-sequence that sheds new light on several still poorly understood aspects of the archeological record in both the Haut-Quercy region and southwestern France in general. The level overlying the Late Magdalenian occupation produced limited evidence for the Azilian and is stratigraphically separated from the Laborian. This latter techno-complex, dated to the end of the Pleistocene and early Holocene, remains poorly documented in the region, having only been previously identified from two sites in the Quercy. The discovery of a recent Laborian (Epilaborian) occupation at Peyrazet presented the ideal occasion for a collaborative study of the diverse archaeological material recovered from this well-understood archaeo-stratigraphic context. A geoarchaeological analysis produced evidence for both surface runoff and the accumulation of coarse deposits (Ă©boulis) as the principal site formation processes. In the southwest area of the site, a reworked lithofacies demonstrates substantial bioturbation in connection with animal burrowing. Although the presence of rodent, bird, fish, and medium-sized mammals (except hare) cannot be definitively connected to human activity, they nevertheless provide important information concerning the environments exploited by hunter-gatherer groups. Larger species are dominated by red deer whose carcasses were partially processed before being introduced to the site, where meat was subsequently removed and marrow consumed. A functional analysis combined with a typo-technological study of the primarily locally- and regionally-procured lithic material revealed evidence for diverse activities having taken place on-site. An ochre fragment, several bone tools and ornaments equally indicate a large variety of tasks to have been carried out during a single, long occupation or several successive visits. A typo-technological comparison of hunting weaponry (microliths) from sites across a substantial area suggests the assemblage to represent either a Laborian/Epilaborian mix or a unique Epilaborian occupation. This latter case would indicate the persistence of older morphotypes alongside the development of new tools forms, a situation already identified at Borie del Rey in the Haut-Agenais but which requires more detailed study supported by new discoveries
Normative volumes and relaxation times at 3T during brain development.
While research has unveiled and quantified brain markers of abnormal neurodevelopment, clinicians still work with qualitative metrics for MRI brain investigation. The purpose of the current article is to bridge the knowledge gap between case-control cohort studies and individual patient care. Here, we provide a unique dataset of seventy-three 3-to-17 years-old healthy subjects acquired with a 6-minute MRI protocol encompassing T1 and T2 relaxation quantitative sequence that can be readily implemented in the clinical setting; MP2RAGE for T1 mapping and the prototype sequence GRAPPATINI for T2 mapping. White matter and grey matter volumes were automatically quantified. We further provide normative developmental curves based on these two imaging sequences; T1, T2 and volume normative ranges with respect to age were computed, for each ROI of a pediatric brain atlas. This open-source dataset provides normative values allowing to position individual patients acquired with the same protocol on the brain maturation curve and as such provides potentially useful quantitative biomarkers facilitating precise and personalized care
Dosage et pistage de peptides Troyens dans les cellules
Les peptides Troyens ou vecteurs sont capables de passer les membranes biologiques et de véhiculer des principes actifs dans le cytoplasme ou le noyau des cellules dans lesquelles ils sont entrés. Les méthodes indirectes utilisées jusqu'à présent pour détecter ces peptides dans les cellules n'ont pas permis d'établir de maniÚre univoque le(s) mécanisme(s) de leur internalisation. La méthode de quantification, basée sur la spectrométrie de masse MALDI-TOF, que nous avons mise au point pour quantifier ces peptides Troyens dans les cellules est développée dans cette revue
Activity of the calcineurin pathway in patients on the liver transplantation waiting list: factors of variability and response to tacrolimus inhibition. Pierre Marquet Institutions and affiliations
International audienceBACKGROUND:We sought to evaluate, in patients on a liver transplantation waiting list, potential biomarkers of the base calcineurin pathway activity with use of a new model of nonstimulated peripheral blood mononuclear cells (PBMC) and ex vivo response to tacrolimus (TAC).METHODS:The calcineurin pathway activity was explored ex vivo in stimulated and nonstimulated PBMC from 19 patients. The inhibition of NFATC1+ translocation to PBMC, expression of intracellular IL-2, and membrane CD25 in different T-cell subsets were measured by multiparametric flow cytometry before and after exposure to TAC. We also studied the influence on the individual response of polymorphisms in 3 key genes of the calcineurin pathway: PPIA, PPP3CA, and IL2RA.RESULTS:All pharmacodynamics profiles closely fitted an I/Imax sigmoid model. Interindividual variability was higher in nonstimulated than in stimulated conditions, as well as in the presence of TAC. IL-2+CD8+ cells at TAC Imax showed the highest interindividual variability, suggesting its usefulness as a biomarker of individual TAC effects integrating many different sources of regulation and variability. Moreover, in the absence of TAC, patients with end-stage liver disease exhibited lower NFATC1 translocation and T-cell activation than healthy volunteers from a previous study under similar conditions. Multivariate statistical analysis showed strong and significant associations between TAC pharmacodynamic parameters and 2 polymorphisms in the gene-coding cyclophilin A (rs8177826 and rs6850).CONCLUSIONS:We show the feasibility of using nonstimulated PBMCs to explore the calcineurin pathway under more physiologic conditions and point toward potential biomarkers for TAC pharmacodynamic monitoring
Les fascines de ligneux en gĂ©nie vĂ©gĂ©tal. Guide technique Office Français de la BiodiversitĂ© et Institut National de Recherche pour lâagriculture, lâalimentation et lâenvironnement.
International audienceLes techniques de gĂ©nie vĂ©gĂ©tal pour le contrĂŽle de lâĂ©rosion en riviĂšre font frĂ©quemment appel aux techniques de fascinage. Ces techniques ancestrales consistent gĂ©nĂ©ralement en la mise en place en pieds de berge de fagots de saules vivants fixĂ©s Ă des pieux. Câest la technique de protection de pied de berge la plus utilisĂ©e dans les ouvrages de gĂ©nie vĂ©gĂ©tal en France, elle y constitue ainsi 26 % des ouvrages de pied de berge (Jaymond et al., 2021). Les fascines sâinsĂšrent le plus souvent dans une combinaison de techniques, chacune apportant sa contribution pour une bonne protection de la berge et/ou du talus. Le fascinage est ainsi rĂ©guliĂšrement combinĂ© Ă dâautres techniques de gĂ©nie vĂ©gĂ©tal ou gĂ©nie civil afin de rĂ©pondre prĂ©cisĂ©ment Ă chaque particularitĂ©, spĂ©cificitĂ©, et besoin du talus ou cours dâeau considĂ©rĂ©. On trouve notamment des associations avec du bouturage, des lits de plants et plançons pour le gĂ©nie vĂ©gĂ©tal et avec de lâenrochement pour le gĂ©nie civil.Bien que simples Ă premiĂšre vue et connues pour leur forte rĂ©sistance mĂ©canique, ces techniques demandent un rĂ©el savoir-faire pour rĂ©sister durablement et connaĂźtre une bonne reprise vĂ©gĂ©tale. Le type dâespĂšces utilisĂ©es, la qualitĂ© du matĂ©riel vĂ©gĂ©tal, la nature du contact avec la terre, la hauteur dâimplantation par rapport Ă la ligne dâeau sont autant de facteurs dĂ©terminants dans la rĂ©ussite et la bonne tenue des ouvrages.Les modalitĂ©s dâapplication des fascines sont variĂ©es, elles peuvent se prĂ©senter sous diffĂ©rentes formes : mortes ou vivantes, en pied de berge ou sur les talus, de petit ou de grand diamĂštre, sous forme de barriĂšre ou de drain. Leurs modalitĂ©s de mise en Ćuvre sont Ă©galement multiples : une ou deux rangĂ©es de pieux ; installation in situ sous forme de fagot prĂ©-confectionnĂ© ou branche par branche ; pied des branches ancrĂ©es ou pas dans la berge ; fixation avec du fil de fer ou de la corde cocoâŠPourtant aucun document technique ne dĂ©crit lâensemble de ces possibilitĂ©s et les avantages et inconvĂ©nients de lâensemble de ces diffĂ©rentes techniques. Les profils techniques disponibles sont souvent similaires et prennent rarement en compte les diffĂ©rentes possibilitĂ©s offertes, ni les contraintes affĂ©rentes. Outre ces formes classiques de fascinage, le terme fascine inclut Ă©galement la fascine dâhĂ©lophytes, Ă©galement un ouvrage de protection/vĂ©gĂ©talisation de pied de berge. Toutefois, cette technique ne sera pas dĂ©crite dans ce guide, on ne sâintĂ©ressera quâaux techniques de fascinages avec des ligneux.Fort de ces constats, le prĂ©sent guide a pour vocation de rĂ©pondre Ă ce manque de document techniques en contribuant Ă lâamĂ©lioration de lâutilisation et la mise en Ćuvre des techniques de fascinage. Lâobjectif est de rendre disponible Ă tous, la diversitĂ© de leur modalitĂ© dâutilisation, et les avantages et inconvĂ©nients de chacune en exposant les diverses applications dans le dĂ©tail. Il sâagit dâabord de dĂ©crire la grande variabilitĂ© des techniques de fascinage, en fournissant des spĂ©cifications techniques et des profils dĂ©taillĂ©s, ainsi que les modalitĂ©s prĂ©cises dâutilisation, leurs limites, leurs avantages et inconvĂ©nients. Lâobjectif finalisĂ© est de mettre Ă portĂ©e de chacun les prĂ©conisations techniques prĂ©cises Ă apporter aux gestionnaires pour la bonne rĂ©alisation de fascines, depuis les matĂ©riaux constitutifs jusquâĂ lâentretien en passant par les modalitĂ©s de mise en Ćuvre et les conditions de milieux appropriĂ©es Ă ce type dâouvrage.Ce document constitue un support technique pratique pour les concepteurs, maĂźtres dâĆuvre, techniciens et maĂźtres dâouvrage ou grand public. Il ne constitue pas une rĂ©ponse Ă toutes les situations en matiĂšre de protection de berge, ni un catalogue de recettes Ă appliquer sans se poser de question.Les techniques dĂ©crites sont rĂ©guliĂšrement combinĂ©es Ă dâautres techniques afin de rĂ©pondre prĂ©cisĂ©ment Ă chaque particularitĂ© et spĂ©cificitĂ© du tronçon de cours dâeau considĂ©rĂ©. La conception dâun ouvrage de stabilisation Ă lâaide de techniques vĂ©gĂ©tales nĂ©cessite des compĂ©tences multiples et pluridisciplinaires aussi bien en botanique, en Ă©cologie mais Ă©galement en sciences de lâingĂ©nieur, pĂ©dologie ou hydraulique en intĂ©grant une connaissance complĂ©mentaire des processus Ă©rosifs et morphodynamiques. La conception dâun ouvrage de gĂ©nie vĂ©gĂ©tal demande un diagnostic et une Ă©tude prĂ©cis et rigoureux, sâappuyant sur une bonne analyse du terrain et dĂ©bouchant sur des plans et spĂ©cifications techniques associĂ©e