53 research outputs found

    The granite hosted gold deposit of Moulin de Chéni (Saint-Yrieix district, Massif Central, France): petrographic, structural, fluid inclusion and oxygen isotope constraints

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    The Moulin de ChĂ©ni orogenic gold deposit is the only granite-hosted deposit of the Saint-Yrieix district, French Massif Central. It occurs in 338±1.5Ma-old peraluminous leucogranites and is characterized by intense microfracturing and bleaching of the granite in relation to pervasive sulfide crystallization. Formation of quartz veins and gold deposition occurred in two successive stages: an early "mesozonal” stage of quartz-sulfide (Fe-As-S) deposition, usually devoid of gold and a late "epizonal” stage of base metal and gold deposition. Both stages postdate peak metamorphism and granite intrusion. The genesis of the deposit is the result of four successive fluid events: (1) Percolation of aqueous-carbonic metamorphic fluids under an assumed lithostatic regime of 400-450°C, at a maximum depth of 13km; (2) Formation of the main quartz lodes with coeval K-alteration and introduction of As and S from aqueous-carbonic fluids percolating along regional faults. Arsenopyrite and pyrite deposition was linked to the alteration of Fe-silicates into K-feldspar and phengite at near-constant iron content in the bulk granite. Temperature was similar to that of the preceding stage, but pressure decreased to 100-50MPa, suggesting rapid uplift of the basement up to 7.5km depth; (3) The resulting extensional tectonic leads to the deposition of gold, boulangerite, galena and sphalerite in brecciated arsenopyrite and pyrite from aqueous fluids during a mixing process. Temperature and salinity decrease from 280 to 140°C and 8.1wt% eq. NaCl to 1.6wt% eq. NaCl, respectively; (4) Sealing of the late fault system by barren comb quartz which precipitated from dilute meteoric aqueous fluids (1.6wt% eq. NaCl to 0.9wt% eq. NaCl) under hydrostatic conditions at 200-150°

    Unrelated stem cell transplantation for severe acquired aplastic anemia: improved outcome in the era of high-resolution HLA matching between donor and recipient

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    Background and Objectives Severe acquired aplastic anemia (SAA) is a potentially fatal bone marrow failure syndrome occurring mainly in children and young adults. Immunosuppressive regimens and hematopoietic stem cell transplantation (HSCT) are the only two available curative treatments. Patients who lack an HLA-identical sibling donor may receive HSCT from an unrelated donor, a strategy historically associated with high mortality rates. Thus, for patients refractory to immunosuppressive regimens, the decision to transplant stem cells from unrelated donors is weighed against supportive care and often represents a dilemma for physicians. We aimed to determine whether outcome after unrelated HSCT has improved in recent years and, if so, to determine the factors responsible for the improvement.Design and Methods We analyzed the outcome of 89 patients (median age 17 years, range 0–52) with acquired SAA undergoing HSCT from an unrelated donor between 1989 and 2004. Cases were consecutively reported to the French Registry (SFGM-TC) by 25 centers.Results Patients transplanted during two successive time-periods (1989–1998 and 1999–2004) had different 5-year survival probabilities (±95% confidence interval): 29±7% and 50±7%, respectively (

    Etude rétrospective du traitement de huit patients afféctés d'un lymphime du manteau en rechute par le protocole HCVAD

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    Le lymphome du manteau est une pathologie rare, reprĂ©sentant 8 Ă  10 % des lymphomes malins non hodgkinien en Europe et aux Etats-Unis. La population concernĂ©e est Ă  prĂ©dominance masculine (sex ratio 1,6/1) et la tranche d'Ăąge oĂč la frĂ©quence la plus Ă©levĂ©e est de 60 Ă  65 ans. Son pronostic au delĂ  de trois ans d'Ă©volutivitĂ© est sombre, avec un fort taux de mortalitĂ©. Sa chimiorĂ©sistance rend les thĂ©rapeutiques peu efficaces et il n'existe aucun protocole connu fixĂ©. Le propos de cette Ă©tude est d'Ă©valuer l'efficacitĂ© d'une polychimiothĂ©rapie sĂ©quentielle, le HCVAD, comme traitement d'induction sur un Ă©chantillon de huit patients en rechute du lymphome du manteau avec, lorsque cela est possible, un traitement de consolidation par allogreffe de moelle osseuse. Les rĂ©sultats de cette Ă©tude rĂ©trospective montrent un taux de rĂ©ponse au traitement d'environ 90 % et une survieĂ  3 ans de 37,5 % dont un patient n'ayant pu avoir de consolidation par allogreffe (antĂ©cĂ©dent d'autogreffe). Les difficultĂ©s de cette Ă©tude ont Ă©tĂ© le faible nombre de patients inclus, rendant l'Ă©chantillon non reprĂ©sentatif au niveau statistique, les historiques hĂ©tĂ©rogĂšnes des traitements dĂ©jĂ  proposĂ©s Ă  ces patients et la quantitĂ© peu importante des publications sur l'HCVAD dans le lymphome du manteau. Au total, l'utilisation d'une polychimiothĂ©rapie sĂ©quentielle suivie d'une consolidation par greffe de moelle osseuse semble prometteur, avec un taux de rĂ©ponse co;mplĂšte significativement plus Ă©levĂ© que dans les traitements plus conventionnels. Selon certaines Ă©tudes, la multiplication des traitements et des rechutes est un facteur d'Ă©chec non nĂ©gligeable, pouvant conduire Ă  proposer ce traitement intensif en premiĂšre ligne, mais dont la toxicitĂ© et les risques de morbiditĂ© et de mortalitĂ©, en particulier chez un sujet ĂągĂ© peut ĂȘtre un facteur limitatif. Des traitements associĂ©s tels que l'utilisation de l'anticorps anti CD20 sont certainement des thĂ©rapeutiques Ă  prendre en compte pour l'amĂ©lioration de la tolĂ©rance et la diminution des toxicitĂ©s.BORDEAUX2-BU SantĂ© (330632101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Qualité de vie à long terme aprÚs autogreffe de cellules souches hématopoïétiques

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    BORDEAUX2-BU Santé (330632101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Identification des motivations et freins à la promotion du don du sang en médecine générale

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    L'objectif de notre Ă©tude Ă©tait d'identifier les motivations et freins Ă  la promotion du don de sang (DDS) en mĂ©decine gĂ©nĂ©rale, de dĂ©terminer si les mĂ©decins gĂ©nĂ©ralistes (MG) se sentaient prĂȘts Ă  ĂȘtre acteurs pour promouvoir cet acte solidaire, et de recueillir l'avis d'un Ă©chantillon de patients pour savoir s'ils seraient rĂ©ceptifs Ă  une information donnĂ©e par leur mĂ©decin traitant. Notre Ă©tude descriptive menĂ©e entre le 5/09 et le 15/12/11, comportait un questionnaire envoyĂ© par email, via l'ordre des mĂ©decins de Gironde, Ă  1591 mĂ©decins gĂ©nĂ©ralistes installĂ©s et thĂ©sĂ©s, et un second, distribuĂ© Ă  une patientĂšle d'un cabinet de mĂ©decine gĂ©nĂ©rale situĂ© Ă  CaudĂ©ran. A travers cette Ă©tude, il ressort que 86 % des patients et des MG sont concernĂ©s par le sujet et que plus de 70 % pensent que le MG a un rĂŽle direct dans la promotion du DDS et la sensibilisation des patients. MG et patients souhaitent ĂȘtre informĂ©s sur les DDS, les lieux de collecte et 90 % seraient favorables Ă  des plaquettes d'informations dans les salles d'attente. 57 % des mĂ©decins aimeraient avoir une formation dans le cadre de la formation mĂ©dicale continue, 68 % pourraient y consacrer du temps dans la consultation. Si le MG adhĂšre Ă  l'idĂ©e de promouvoir le sujet, investi d'une mission de santĂ© publique pour renforcer la prise de conscience individuelle, le manque de temps dans la consultation et les nombreuses sollicitations dont il est l'objet constituent des freins majeurs. Concernant les patients, prĂšs de 60 % seraient plus rĂ©ceptifs si le MG abordait le sujet en consultation et pensent que leur comportement aurait changĂ© s'ils avaient Ă©tĂ© sensibilisĂ©s dĂšs le plus jeune Ăąge par leur MG. Devant les besoins croissants en unitĂ©s de sang, et la difficultĂ© de trouver de nouveaux donneurs, promouvoir le DDS grĂące Ă  la formation et la sensibilisation des MG tĂŽt dans leur cursus, mais aussi des autres professionnels de santĂ©, en collaboration avec l'Etablissement français du sang, peut ĂȘtre une solution.BORDEAUX2-BU SantĂ© (330632101) / SudocSudocFranceF

    Etude de la qualité de vie des patients plus de 5 ans aprés allogreffe de moelle osseuse

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    BORDEAUX2-BU Santé (330632101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Les Mycotoxines dans l'alimentation en Europe

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    LYON1-BU Santé (693882101) / SudocSudocFranceF

    The granite hosted gold deposit of Moulin de Chéni (Saint-Yrieix district, Massif Central, France): petrographic, structural, fluid inclusion and oxygen isotope constraints

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    The Moulin de ChĂ©ni orogenic gold deposit is the only granite-hosted deposit of the Saint-Yrieix district, French Massif Central. It occurs in 338±1.5 Ma-old peraluminous leucogranites and is characterized by intense microfracturing and bleaching of the granite in relation to pervasive sulfide crystallization. Formation of quartz veins and gold deposition occurred in two successive stages: an early “mesozonal” stage of quartz-sulfide (Fe-As-S) deposition, usually devoid of gold and a late “epizonal” stage of base metal and gold deposition. Both stages postdate peak metamorphism and granite intrusion. The genesis of the deposit is the result of four successive fluid events: (1) Percolation of aqueous-carbonic metamorphic fluids under an assumed lithostatic regime of 400–450 °C, at a maximum depth of 13 km; (2) Formation of the main quartz lodes with coeval K-alteration and introduction of As and S from aqueous-carbonic fluids percolating along regional faults. Arsenopyrite and pyrite deposition was linked to the alteration of Fe-silicates into K-feldspar and phengite at near-constant iron content in the bulk granite. Temperature was similar to that of the preceding stage, but pressure decreased to 100–50 MPa, suggesting rapid uplift of the basement up to 7.5 km depth; (3) The resulting extensional tectonic leads to the deposition of gold, boulangerite, galena and sphalerite in brecciated arsenopyrite and pyrite from aqueous fluids during a mixing process. Temperature and salinity decrease from 280 to 140 °C and 8.1 wt% eq. NaCl to 1.6 wt% eq. NaCl, respectively; (4) Sealing of the late fault system by barren comb quartz which precipitated from dilute meteoric aqueous fluids (1.6 wt% eq. NaCl to 0.9 wt% eq. NaCl) under hydrostatic conditions at 200–150 °C

    High hydrostatic pressure treatment for the inactivation of Staphylococcus aureus in human blood plasma.

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    For the past 30years, pressure inactivation of microorganisms has been developed in biosciences, in particular for foods and more recently for biological products, including pharmaceutical ones. In many past studies, the effect of high hydrostatic pressure (HHP) processes on pathogens focused mainly on the effect of an increase of the pressure value. To assure the safety of pharmaceutical products containing fragile therapeutic components, development of new decontamination processes at the lowest pressure value is needed to maintain their therapeutic properties. The aim of this study was therefore to evaluate the impact of the process parameters characterizing high-pressure treatments [such as the pressurization rate (PR) and the application mode (AM)] on the inactivation of pathogens, in particular to determine how these parameters values could help decrease the pressure value necessary to reach the same inactivation level. The effect of these physical parameters was evaluated on the inactivation of Staphylococcus aureus ATCC 6538 which is an opportunistic pathogen of important relevance in the medical, pharmaceutical and food domains. Human blood plasma was chosen as the suspension medium because of its physiological importance in the transfusion field. It was shown that the optimization of all the selected parameters could lead to a high inactivation level (≈5log(10) decrease of the initial bacterial load) at a pressure level as low as 200MPa, underlining some synergistic effects among these parameters. Complete inactivation of the initial bacterial population was achieved for the following conditions: PR=50MPas(-1), AM=5×2min, T≈-5°C and P=300MPa
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