13 research outputs found

    Evaluation of a novel nanocrystalline hydroxyapatite paste Ostim® in comparison to Alpha-BSM® - more bone ingrowth inside the implanted material with Ostim® compared to Alpha BSM®

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study was to evaluate the performance a newly developed nanocrystalline hydroxyapatite, OSTIM<sup>® </sup>following functional implantation in femoral sites in thirty-eight sheep for 1, 2 or 3 months. Ostim<sup>® </sup>35 was compared to an established calcium phosphate, Alpha BSM<sup>®</sup>.</p> <p>Methods</p> <p>Biomechanical testing, μ-CT analysis, histological and histomorphological analyses were conducted to compare the treatments including evaluation of bone regeneration level, material degradation, implant biomechanical characteristics.</p> <p>Results</p> <p>The micro-computed tomography (μCT) analysis and macroscopic observations showed that Ostim<sup>® </sup>seemed to diffuse easily particularly when the defects were created in a cancellous bone area. Alpha BSM<sup>® </sup>remained in the defect.</p> <p>The performance of Ostim was good in terms of mechanical properties that were similar to Alpha BSM<sup>® </sup>and the histological analysis showed that the bone regeneration was better with Ostim<sup>® </sup>than with Alpha BSM<sup>®</sup>. The histomorphometric analysis confirmed the qualitative analysis and showed more bone ingrowth inside the implanted material with Ostim<sup>® </sup>when compared to Alpha BSM <sup>® </sup>at all time points.</p> <p>Conclusions</p> <p>The successful bone healing with osseous consolidation verifies the importance of the nanocrystalline hydroxyapatite in the treatment of metaphyseal osseous volume defects in the metaphyseal spongiosa.</p

    Evaluation du stress oxydatif radicalaire associé à l'utilisation d'un circuit extracorporel

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    L'IMPLICATION POSSIBLE DES RADICAUX LIBRES OXYGENES (RLO) DANS LA GENESE DE CERTAINS DESORDRES CARDIOVASCULAIRES FAIT L'OBJET DE NOMBREUSES ETUDES. NOUS NOUS SOMMES INTERESSE (sic) DANS CE TRAVAIL A DEUX SITUATIONS CLINIQUES, ASSOCIEES A DES DYSFONCTIONS CARDIOVASCULAIRES SPECIFIQUES, DANS LESQUELLES LES ESPECES RAICALAIRES SONT SUSCEPTIBLES D'ETRE IMPLIQUEES : IL S'AGIT DE LA CHIRURGIE CARDIAQUE SOUS CIRCULATION EXTRACORPORELLE (CEC) ET DE L'HEMODIALYSE (HD). CES DEUX TECHNIQUES SONT ASSOCIEES A L'UTILISATION D'UN CIRCUIT EXTRACORPOREL POUVANT PARTICIPER A L'ETABLISSEMENT D'UN STRESS OXYDATIF RADICALAIRE, AUQUEL S'AJOUTENT DES CIRCONSTANCES SPECIFIQUES A CHAQUE SITUATION. L'OBJECTIF DE NOS TRAVAUX A ETE 1) DE DEFINIR LA NATURE DU STRESS OXYDATIF RENCONTRE RESPECTIVEMENT AU COURS DE LA CHIRURGIE CARDIAQUE SOUS LE CEC ET DE L'HD PUIS 2) D'ENVISAGER UNE STRATEGIE CIBLEE PERMETTANT EVENTUELLEMENT DE DIMINUER LE STRESS OXYDATIF, ET PAR VOIE DE CONSEQUENCE LES DYSFONCTIONNEMENTS ASSOCIES CHEZ LES PATIENTS.LA CHIRURGIE CARDIAQUE EST ASSOCIEE A DEUX SITUATIONS PHYSIOPATHOLOGIQUES DISTINCTES SUSCEPTIBLES D'ETRE ASSOCIEES A UNE PRODUCTION RADICALAIRE : D'UNE PART LA CEC PROPREMENT DITE, D'AUTRE PART LA SEQUENCE ISCHEMIE-REPERFUSION MYOCARDIQUE ASSOCIEE A DES LESIONS SPECIFIQUES DITES "DE REPERFUSION". NOUS AVONS PU DEMONTRER, DANS LE CADRE DE CHIRURGIES CORONARIENNES SOUS CEC 1) QU'IL SE PRODUISAIT UNE LIBERATION D'ESPECES RADICALAIRES MISE EN EVIDENCE PAR LA TECHNIQUE DE "SPIN TRAPPING" UTILISANT LE PBN, ASSOCIEE A LA RESONANCE PARAMAGNETIQUE ELECTRONIQUE; 2) QUE CETTE LIBERATION RADICALAIRE ETAIT MAJORITAIREMENT D'ORIGINE SYSTEMIQUE DES LES PREMIERES PHASES DE LA CEC ET JUSQU'A LA FIN DE CELLE-CI, LA LIBERATION PROPRE AU TERRITOIRE MYOCARDIQUE ETANT MINORITAIRE FACE A CE PHENOMENE; 3)...DIJON-BU MĂ©decine Pharmacie (212312103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

    REGARD sur les bibliothèques publiques du Québec et d’ailleurs

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    Ce document est la sixième édition du désormais traditionnel regard porté sur l’année écoulée en bibliothèque publique. Un regard qui, s’élevant au-delà de la veille que nous réalisons au jour le jour, nous permet d’embrasser les mouvements de fond et les tendances qui s’en dégagent. L’année 2023 aura eu cela de particulier que les bibliothèques publiques se sont retrouvées au cœur d’enjeux qui ont fait l’actualité mois après mois. Il s\u27agit donc d\u27un important rapport concernant les bibliothèques québécois

    Devising tissue ingrowth metrics: a contribution to the computational characterization of engineered soft tissue healing

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    International audienceThe paradigm shift brought about by the expansion of tissue engineering and regenerative medicine away from the use of biomaterials, currently questions the value of histopathologic methods in the evaluation of biological changes. To date, the available tools of evaluation are not fully consistent and satisfactory for these advanced therapies.Wehave developed a new, simple and inexpensive quantitative digital approach that provides key metrics for structural and compositional characterization of the regenerated tissues. For example, metrics provide the tissue ingrowth rate (TIR) which integrates two separate indicators; the cell ingrowth rate (CIR) and the total collagen content (TCC) as featured in the equation, TIR%=CIR%+TCC%. Moreover a subset of quantitative indicators describing the directional organization of the collagen (relating structure and mechanical function of tissues), the ratio of collagen I to collagen III (remodeling quality) and the optical anisotropy property of the collagen (maturity indicator) was automatically assessed as well. Using an image analyzer, all metrics were extracted from only two serial sections stained with either Feulgen&Rossenbeck (cell specific) or Picrosirius Red F3BA (collagen specific). To validate this new procedure, threedimensional(3D) scaffolds were intraperitoneally implanted in healthy and in diabetic rats. It was hypothesized that quantitatively, the healing tissue would be significantly delayed and of poor quality in diabetic rats in comparison to healthy rats. In addition, a chemically modified 3D scaffold wassimilarly implanted in a third group of healthy rats with the assumption that modulation of the ingrown tissue would be quantitatively present in comparison to the 3D scaffold-healthy group. After 21 days of implantation, both hypotheses were verified by use of this novel computerized approach. When the two methods were run in parallel, the quantitative results revealed fine details and differences not detected by the semi-quantitative assessment, demonstrating the importance of quantitative analysis in the performance evaluation of soft tissue healing. This automated and supervised method reduced operator dependency and proved to be simple, sensitive, cost-effective and time-effective. It supports objective therapeutic comparisons and helps to elucidate regeneration and the dynamics of a functional tissue

    Biological tolerance of different materials in bulk and nanoparticulate form in a rat model: sarcoma development by nanoparticles

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    In order to study the pathobiological impact of the nanometre-scale of materials, we evaluated the effects of five different materials as nanoparticulate biomaterials in comparison with bulk samples in contact with living tissues. Five groups out of 10 rats were implanted bilaterally for up to 12 months with materials of the same type, namely TiO2, SiO2, Ni, Co and polyvinyl chloride (PVC), subcutaneously with bulk material on one side of the vertebral column and intramuscularly with nanoparticulate material on the contralateral side. At the end of each implantation time, the site was macroscopically examined, followed by histological processing according to standard techniques. Malignant mesenchymal tumours (pleomorphic sarcomas) were obtained in five out of six cases of implanted Co nanoparticle sites, while a preneoplastic lesion was observed in an animal implanted with Co in bulk form. In the Ni group, all animals rapidly developed visible nodules at the implanted sites between 4 and 6 months, which were diagnosed as rhabdomyosarcomas. Since the ratio of surface area to volume did not show significant differences between the Ni/Co group and the TiO2/SiO2/PVC group, we suggested that the induction of neoplasia was not mediated by physical effects, but was mediated by the well-known carcinogenic impact of Ni and Co. The data from the Co group show that the physical properties (particulate versus bulk form) could have a significant influence on the acceleration of the neoplastic process
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