Готові списки джерел за темами / Etudes in vitro et in vivo

Добірка наукової літератури з теми "Etudes in vitro et in vivo"

Автор: Grafiati

Опубліковано: 25 травня 2022

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Статті в журналах з теми "Etudes in vitro et in vivo":

CORPET, D. E. "Etude de l'écologie microbienne de l'intestin : modèles in vitro, in vivo et mathématiques." Revue Scientifique et Technique de l'OIE 8, no. 2 (June 1, 1989): 375–89. http://dx.doi.org/10.20506/rst.8.2.407.

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Vivares, Christian P., Panayota Papayanni, and Jean-Marie Quiot. "Etude in vivo et in vitro de la pathogénicité de Hexamita nelsoni schlicht et mackin 1968, vis à vis des huîtres." Aquaculture 67, no. 1-2 (December 1987): 165–70. http://dx.doi.org/10.1016/0044-8486(87)90022-6.

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Mateo, J., L. Teisseire, B. Cholley, B. Teisseire, and D. Payen. "Prévention de l’atteinte vasculaire par l’hémoadsorption au cours du choc septique expérimental: Etude in vivo et in vitro." Annales Françaises d'Anesthésie et de Réanimation 12, no. 12 (1993): R223. http://dx.doi.org/10.1016/s0750-7658(16)30223-4.

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Cassar, I., and F. Bacou. "POLYMORPHISME DE L'ACETYL- ET DE LA BUTYRYLCHOLINESTERASE AU COURS DE LA DIFFERENCIATION EMBRYONNAIRE DES MUSCLES DE LAPIN: ETUDE IN VIVO ET IN VITRO." Reproduction Nutrition Développement 29, Suppl. 1 (1989): 19. http://dx.doi.org/10.1051/rnd:19890727.

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Boureau, H., P. Bourlioux, C. Guichet, and M. B. Romond. "Anaerobies et resistance a la colonisation par C. difficile. Etude in vitro et in vivo des activités enzymatiques vis-à-vis des mucines intestinales." Médecine et Maladies Infectieuses 20 (December 1990): 67–70. http://dx.doi.org/10.1016/s0399-077x(05)80060-5.

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BERNARD, A., Mathilde FLEITH, Hélène CARLIER, and J. S. HUGON. "Etude « in vivo » et « in vitro » de l'absorption intestinale de l'acide oléique. Influence de la solubilisation des lipides par le taurocholate de sodium." Reproduction Nutrition Développement 26, no. 5B (1986): 1198. http://dx.doi.org/10.1051/rnd:19860823.

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Lavisse, S., A. Paci, V. Rouffiac, P. Péronneau, P. Opolon, E. Fattal, A. Roche, and N. Lassau. "Caracterisation ultrasonore in vitro de microparticules de PLGA et etude preliminaire in vivo sur des tumeurs sous-cutanees de melanome B16 pour une application de produit de contraste ultrasonore." Journal de Radiologie 86, no. 10 (October 2005): 1406. http://dx.doi.org/10.1016/s0221-0363(05)75710-3.

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Lavisse, S., A. Paci, V. Rouffiac, P. Péronneau, P. Opolon, E. Fattal, A. Roche, and N. Lassau. "RECH6 Caracterisation ultrasonore in vitro de microparticules de PLGA et etude preliminaire in vivo sur des tumeurs sous-cutanees de melanome B16 pour une application de produit de contraste ultrasonore." Journal de Radiologie 86, no. 10 (October 2005): 1553. http://dx.doi.org/10.1016/s0221-0363(05)76269-7.

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Jacqueline, C., J. Caillon, and G. Potel. "Linézolide, données récentes expérimentales in vitro et in vivo." Antibiotiques 7, no. 4 (December 2005): 225–33. http://dx.doi.org/10.1016/s1294-5501(05)80455-8.

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Gouget, B., and J. Fonteneau. "Biocapteurs in vitro, ex vivo, in vivo et “point of care testing (POCT)”." Revue Française des Laboratoires 1997, no. 292 (April 1997): 73–76. http://dx.doi.org/10.1016/s0338-9898(97)80041-8.

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Дисертації з теми "Etudes in vitro et in vivo":

Pérault-Pochat, Marie-Christine. "Etudes in vivo et in vitro de plusieurs interactions avec les psychotropes." Paris 6, 1995. http://www.theses.fr/1995PA066806.

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Ce travail en deux parties est consacre a l'etude d'un certain nombre d'interactions medicamenteuses entre des antidepresseurs, des anxiolytiques et un antihistaminique h1. La premiere concerne l'etude chez l'homme des effets de l'association de ces medicaments sur les performances psychomotrices (pcfl, crt, test de pauli, test du tapping), mnesiques (tests des images, de sternberg, de buschke), sur les modifications de l'equilibre (posturographie) et sur l'humeur des sujets (echelles d'auto-evaluation de l'humeur et de la vigilance). Certaines de ces etudes pharmacodynamiques etaient couplees a des dosages plasmatiques ou salivaires des medicaments, en vue de rechercher une eventuelle interaction d'origine pharmacocinetique. Les resultats obtenus nous ont permis de valider une methodologie adaptee a la mise en evidence de modifications de fonctions du systeme nerveux central lors de l'association de certaines molecules. Cette methodologie s'avere interessante soit au cours du developpement de nouveaux principes actifs, soit apres commercialisation pour comprendre certains faits cliniques. La deuxieme partie presente les resultats obtenus a l'aide deux modeles in vitro susceptibles d'expliquer les interactions observees chez l'homme. L'utilisation de microsomes ou d'hepatocytes de rats ne s'est pas averee exploitable dans la recherche de variations d'activites enzymatiques pouvant resulter de l'association des medicaments. Il apparait qu'aux doses pharmacologiques, les donnees obtenues chez l'animal ne sont pas obligatoirement transposables a l'homme en raison de l'existence de systemes enzymatiques parfois differents. Par ailleurs, le temps de survie des hepatocytes etant limite a 48 heures, ce second modele ne nous a pas permis de mettre en evidence les phenomenes d'induction ou d'inhibition enzymatique qui apparaissent habituellement apres plusieurs jours d'association des produits

Bun, Sok-Siya. "Etudes in vitro et in vivo du métabolisme et des interactions médicamenteuses du paclitaxel." Aix-Marseille 2, 2003. http://www.theses.fr/2003AIX22954.

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FERRI, BODIN MANUELLE. "Etudes in vitro et in vivo des interactions prunus - plum pox virus (ppv)." Montpellier, ENSA, 2000. http://www.theses.fr/2000ENSA0025.

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Le plum pox virus (ppv) est un organisme de quarantaine responsable de la sharka, maladie majeure des arbres fruitiers du genre prunus. Peu de sources de resistance sont disponibles actuellement. L'evaluation des ressources genetiques vis-a-vis du ppv doit prendre en compte la perennite de ces especes et etre realisee en conditions confinees. Une demarche experimentale a ete developpee in vitro pour l'etude des interactions prunus - ppv. La variabilite des prunus et de l'agent pathogene a ete prise en compte a travers 6 genotypes et 9 isolats viraux. Une methodologie d'etablissement, de maintien et de multiplication d'une collection de souches virales in vitro a ete developpee sur le genotype sensible, le clone gf 8-1 de prunier mariana. Differents facteurs intervenant dans l'inoculation par greffage in vitro ont ete etudies. Le suivi de la propagation systemique du virus a ete mene in vitro et in vivo, a l'aide de la demarche amap de modelisation de l'architecture des arbres. L'optimisation de la methode d'inoculation in vitro a ete realisee sur le prunier mariana gf 8-1 et le clone resistant p1908 de prunus davidiana. Un gradient de contamination decroissant vers l'apex a ete mis en evidence in vitro et in vivo chez le genotype sensible. Aucun genotype immum n'a ete detecte, mais des resistances partielles probablement liees au mouvement systemique ont ete mises en evidence in vitro comme in vivo. L'inoculation par greffage in vitro de prunus constitue maintenant un outil fiable permettant d'apprehender les relations plante - virus, d'evaluer le comportement de genotypes issus de l'amelioration conventionnelle ou obtenus par transgenese et d'etudier le determinisme genetique de la resistance.

Cunat, Lisiane Burnel Daniel. "BIODISPONIBILITE DE L'ALUMINIUM DANS L'INTESTIN. ETUDES IN VITRO ET IN VIVO CHEZ LE RAT /." [S.l.] : [s.n.], 1999. ftp://ftp.scd.univ-metz.fr/pub/Theses/1999/Cunat.Lisiane.SMZ9931.pdf.

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RIECK, PETER WOLFGANG. "Fgf2 et cicatrisation de la cornee : etudes in vitro et in vivo (doctorat : biol. cell. mol.)." Paris 5, 1996. http://www.theses.fr/1996PA05W075.

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MARIN, JEAN. "Mecanisme d'action et activite biologique du poly (a). Poly (u) : etudes in vitro et in vivo." Paris 11, 1992. http://www.theses.fr/1992PA112124.

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Notre etude a porte sur le mecanisme d'action d'un immunomodulateur: le poly (a). Poly (u). La premiere partie du travail a consiste en l'etude de la liaison et de l'internalisation du poly (a). Poly (u) dans la lignee murine monocyte/macrophage j774a#1 et de la mesure de la stimulation de la 2-5a synthetase. Les experiences realisees a l'aide de poly (a). Poly (u) marque au #3#2p en ses extremites 5 montrent que ce polyribonucleotide se lie aux cellules par un processus dependent de la temperature, partiellement reversible et par l'intermediaire d'une seule classe de sites (kd=10,00,09 10##2 g/l, bmax=13,35,3 10##3 g/l/10#6 cellules). Des experiences d'inhibition-competition montrent que la liaison s'etablit par des structures reconnaissant les polynucleotides simple et double chaine, et l'adn. Les experiences realisees avec du poly (a). Poly (u) marque sur une seule chaine indiquent que ce compose penetre dans la cellule sous forme double brin gardant une certaine stabilite pendant au moins 4 heures. L'autoradiographie des cellules incubees en presence de poly (a). Poly (u) tritie montre son accumulation au niveau des noyaux. La fixation du poly (a). Poly (u) est correlee avec une activation de la 2-5a synthetase cependant un ecart est observe entre la valeur du kd et la concentration induisant une stimulation maximale de la 2-5a synthetase (1 microgramme/ml). La deuxieme partie de notre travail a porte sur l'etude des cytokines impliquees dans la stimulation de la 2-5a synthetase par le poly (a). Poly (u). Cette etude montre qu'elle peut etre bloquee par des anticorps anti il-6 et que cet arn double brin stimule la production d'il-6 par ces cellules. L'etude des effets directs des cytokines sur la 2-5a synthetase suggerent que l'il-6 pourrait agir en tant que cofacteur de l'ifn-alpha. La derniere partie de ce travail a consiste en l'etude in vivo chez la souris balb/c des effets biologiques du poly (a). Poly (u) sur deux activites mediees par l'il-6: la stimulation de la 2-5a synthetase et la production d'anticorps. Cet arn double brin stimule la 2-5a synthetase differentes voies d'administration: intraperitoneale, intraveineuse et intranasale, ainsi que la production d'anticorps anti dnp par les voies intraperitoneales et sous cutanees

Picard, Nicolas. "Etudes in vitro et in vivo du métabolisme du mycophénolate et des interactions métaboliques entre médicaments immunosuppresseurs." Limoges, 2005. http://aurore.unilim.fr/theses/nxfile/default/5e16d2f3-56fd-45eb-8f46-df30fc9267e3/blobholder:0/2005LIMO310G.pdf.

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Les médicaments immunosuppresseurs présentent une fenêtre thérapeutique étroite et sont donc soumis au Suivi Thérapeutique Pharmacologique (STP). Le métabolisme, pouvant être responsable de variations d'exposition et d'interactions médicamenteuses, est un facteur à prendre en compte dans le choix des associations thérapeutiques et des doses administrées. Ce travail concerne l'étude du métabolisme de l'acide mycophénolique (MPA, forme active du mycophénolate mofétil, Cellcept®) et des interactions métaboliques entre médicaments immunosuppresseurs. Les voies métaboliques de phase I et de phase II du MPA ont été identifiées in vitro (métabolites, isoformes enzymatiques, localisation tissulaire). Ces études ont mis en évidence le rôle majoritaire des UGT 1A9 et 2B7 dans la formation des deux métabolites principaux du MPA (MPA-phényl-glucuronide, MPAG et MPA-acyl-glucuronide, AcMPAG). Le polymorphisme génétique de l'UGT 1A9 n'a pas pu être associé à des variations des concentrations sanguines du MPAG. En revanche, la mutation G-840A de l'UGT 2B7 semble à l'origine d'une exposition variable à l'AcMPAG, métabolite suspecté d'être à l'origine d'une part de la toxicité du MMF. Nous avons mis en évidence chez des patients transplantés rénaux des différences d'exposition au MPA et à ses métabolites en fonction de l'immunosuppresseur associé (ciclosporine, tacrolimus, sirolimus). Elles impliquent vraisemblablement deux interactions différentes : un effet de la ciclosporine sur l'excrétion biliaire des métabolites du MPA et un effet du tacrolimus sur la pharmacocinétique du MPA, dont la nature exacte reste à étudier. Enfin, à partir de résultats obtenus in vitro noussuggérons que l'interaction métabolique existant entre la ciclosporine et le sirolimus fait essentiellement intervenir le CYP 3A4. Le CYP 3A5, qui contribue largement à la biodisponibilité de la molécule lorsqu'il est exprimé, n'interviendrait que de façon minoritaire dans cette interaction
The immunosuppressive drugs have a narrow therapeutic window and thus require Therapeutic Drug Monitoring (TDM). Metabolism could lead to changes in drug exposure as well as to drug-drug interactions. It should be considered for the choice of drug combination and dosages. This work focuses on the metabolism of mycophenolic acid (MPA, the active moiety of mycophenolate mofetil, Cellcept®) and drug-drug interactions between immunosuppressive drugs. MPA phase I and phase II metabolic pathways were characterized in vitro (metabolites, enzyme isoforms, tissue locations). These studies showed that UGT 1A9 and UGT 2B7 are the main contributors to the production of the two main MPA metabolites (MPA-phenyl-glucuronide, MPAG and MPA-acyl-glucuronide, AcMPAG). UGT 1A9 genetic polymorphism was not associated with changes in MPAG plasma concentrations. On the contrary, the UGT 2B7 G-840A mutation influenced AcMPAG exposure, a metabolite presumably responsible for a part of MMF toxicity. In renal transplant patients, we observed variations in the exposure to MPA and metabolite, depending on the immunosuppressive drug associated (cyclosporin, tacrolimus, or sirolimus). This seems to involve two different interactions: an effect of cyclosporin on MPAG biliary excretion as well as an effect of tacrolimus on MPA pharmacokinetics (of which the mechanism remains to be explored). Finally, based on in vitro experiments, we suggestthat the metabolic interaction between cyclosporin and sirolimus mainly involves CYP 3A4. CYP 3A5, which largely contributes to sirolimus bioavailability (when expressed), would only play a minor role in this interaction

Richard, Bruno. "Etudes metabolique et pharmacocinetique de la mitoxantrone (novantrone) : apport de differents modeles in vivo et in vitro." Aix-Marseille 2, 1990. http://www.theses.fr/1990AIX22984.

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Le, Marec Olivier. "Relations structure-activité du 26RFa, un neuropeptide orexigène. Etudes pharmacochimiques in vitro et in vivo." Rouen, 2011. http://www.theses.fr/2011ROUES019.

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Le 26RFa, dernier représentant de la dfamille des peptides RFamides caractérisé est le ligand endogène du GPR103. Les données de la littérature indiquent que le 26RFa participe au contrôle de la prise alimentaire, de l'insulinémie, de l'homéostasie hydrominérale et de l'ostéogénèse et que son fragment C-terminal (26RFa(10-26)) mime ses effets orexigène et insulinostatique. L'étude des relations structure-activité du 26RFa que nous avons menée montre que le 26RFa(10-26) est le fragment minimal iso-actif, et que le 26RFa(20-26) est la forme moléculaire la plus pertinente pour développer les ligands du GPR103. La substitution de la Ser23 du 26RFa(20-26) par une norvaline conduit à un analogue trois fois plus puissant. Nous montrons aussi que la présence d'une fonction N- terminale libre n'est pas indispensable à l'activité du 26RFa et que le résidu Phe26 peut être éliminé sans perte d'activité dans l'analogue N-benzyl-26RFa(1-25). D'autre part, nous avons étudié les effets du 26RFa sur l'axe gonadotrope chez le rat. Nos résultats indiquent que le 26RFa stimule la libération de LH et FSH par des explants hypophysaires de rats, que le GPR103 est exprimé dans l'hypophyse à tous les stades du développement, que le 26RFa exerce un effet hypophysiotrope in vivo après administration centrale ou systémique chez la ratte cyclique ou ovariectomisée, indiquant que le 26RFa stimule l'axe gonadotrope à la fois au niveau hypothalamique et hypophysaire. Enfin, l'injection centrale de 26RFa provoque une diminution du taux sérique de prolactine chez les femelles cycliques en disoestrus et les rats mâles adultes. Les effets stimulateurs du 26RFa et de ses analogues sur l'axe gonadotrope ouvrent de nouvelles perspectives thérapeutiques pour le contrôle de la fertilité, aux côtés des applications potentielles dans le traitement des troubles de l'homéostasie énergétique du développement osseux
The 26RFa, last member of the RFamide peptide family, has been characterized as the endogenous ligand of the GPR103. The literature indicates that the 26RFa participates to the control of food intake, insulinemia, hydromineral homeostasis and oesteogenesis and that its C-terminal counterpart (26RFa(10-26)) mimics its oreigenic and insulinostatic effects. The structure-activity relationships of 26RFa that we led shows that 26RFa(10-26) is the minimal iso-active fragment, and that the 26RFa(20-26) is the more relevent molecular form to develop GPR103 ligands. The Ser23 substitution of the 26RFa(20-26) by a norvaline lead to an analog three times more potent. We also demonstrate that the presence of a free N-terminal function is not essential to 26 RFa activity and that the Phe26 moiety may be eliminated without loss of activity with the N-benzyl-26RFa(1-25). Besides, we studied the effects of the 26RFa on gonadotropic axis in rat. Our results indicate that the 26RFa stimulates LH and FSH release from rat pituitary explants, that GPR103 is expressed in hypophysis all along the development, that 26RFa mediates an in vivo hypophysiotropic effects after central or systemic administration in cyclic or ovariectomized rat, indicating that the 26RFa stimulates the gonadotropic axis on hypothalamic and ptuitary levels. At last, central injection of 26RFa evokes a decrease of prolactin plasma levels in females in di-oestrus as well as in male adult rats. The stimulatory effects of the 26RFa and its analog on gonadotropic axis open new therapeutic prospects for the control of fertility, besides potential applications in the treatment of the troubles of energetic hoeostasis of bone development

LU, JIANXI. "La formation osseuse lors de l'implantation de bioceramiques poreuses - etudes in vitro et in vivo -." Paris 7, 1997. http://www.theses.fr/1997PA077133.

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Pour realiser ces travaux, deux ceramiques poreuses de microstructure identique (porosite 50%, macropores 100 a 300 m, connexions inter-pores 30 a 100 m), hydroxyapatite (ha) et beta phosphate tricalcique (-tcp), ont ete elaborees. Des etudes in vitro (cytotoxicite et cytofonctionnalite) et in vivo (implantations chez le lapin et le mouton) ont ete effectuees. L'etude in vitro demontre que les deux ceramiques sont non toxiques, et que la biocompatibilite de l'ha est meilleure que celle du -tcp. La degradation de l'ha et du -tcp est tres faible dans le milieu de culture, et peut etre influencee indirectement par les osteoblastes. Elle est cependant insuffisante pour induire une modification de composition et de microstructure des materiaux. Les connexions inter-pores ont un role preponderant : les osteoblastes humains peuvent les traverser, s'installer et proliferer a l'interieur des macropores a condition que leur taille minimum soit de 20 m (la valeur ideale se situant entre 40 et 80 m). L'etude in vivo demontre que la taille des connexions inter-pores doit etre superieure a 50 m pour favoriser l'apport vasculaire et nutritionnel des tissus et permettre la formation du tissu osseux mineralise a l'interieur des macropores ; alors que 20 m suffisent pour le passage des cellules et la formation du tissu chondroide. Dans les materiaux resorbables, la resorption augmente la porosite, mais la densite des pores et des connexions se modifie peu ; aussi cette densite joue un role plus important que la taille. Pour les materiaux non resorbables en revanche, taille et densite ont la meme importance. Nous avons constate que le potentiel de reparation osseuse spontanee est plus important en site osseux cortical qu'en site spongieux. Il est plus eleve en site cortical chez le mouton que chez le lapin. Apres implantation, la biofonctionnalite des ceramiques differe significativement selon le site (spongieux, cortical et medullaire). L'activite de degradation du materiau est plus importante en site medullaire. La neoformation osseuse est plus elevee en site cortical. L'absorptiometrie biphotonique (dxa) peut etre utilisee pour l'evaluation des ceramiques phosphocalciques, mais cette methode non invasive necessite des travaux ulterieurs afin d'en ameliorer les performances dans cette application.

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Книги з теми "Etudes in vitro et in vivo":

Macieira-Coelho, Alvaro. Biology of normal proliferating cells in vitro: Relevance for in vivo aging. Basel: Karger, 1988.

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Частини книг з теми "Etudes in vitro et in vivo":

Trottmann, Christian. "«Comedit, deditque viro suo». La syndérèse entre sensualité et intellect dans la théologie morale au tournant du second quart du XIIIe siècle." In Textes et Etudes du Moyen Âge, 161–87. Turnhout: Brepols Publishers, 2005. http://dx.doi.org/10.1484/m.tema-eb.3.2197.

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Sadeu, J. C., and D. Nogueira. "Folliculogenesis and oogenesis in vivo and in vitro, in humans females." In Physiologie, pathologie et thérapie de la reproduction chez l’humain, 3–23. Paris: Springer Paris, 2011. http://dx.doi.org/10.1007/978-2-8178-0061-5_1.

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Kolb, Gert, N. Runkel, K. Bössenrodt, T. Foitzik, M. Kirchengast, and H. J. Buhr. "In vitro und in vivo Wirkung von Endothelin-1 (ET-1) und eines selektiven ET-A Rezeptorantagonisten (ET-RA) auf die intestinale Kontraktilität bei experimenteller Pankreatitis." In Deutsche Gesellschaft für Chirurgie, 41–43. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-60133-0_10.

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Chabannon, Christian, and Chiara Bonini. "Structure of and Signalling Through Chimeric Antigen Receptor." In The EBMT/EHA CAR-T Cell Handbook, 3–5. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-94353-0_1.

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AbstractChimeric antigen receptor (CAR) is a synthetic transmembrane protein expressed at the surface of immune effector cells (IECs) that are reprogrammed either in vitro or in vivo (June et al. 2018; June and Sadelain 2018). Techniques for genetic engineering of autologous or allogeneic IECs are described in the next chapter. The synthetic CAR incorporates several functional domains. The extracellular domain is composed of a single chain variable fragment (ScFV) of immunoglobulin and recognizes the “tumour” antigen. The clinical relevance of the selected tumour antigen—with a view to minimize “on-target/off-tumour” side effects—is discussed in the third chapter of this section. Bispecific and trispecific CARs are currently being evaluated in preclinical and early clinical trials (Bielamowicz et al. 2018; Shah et al. 2020). The use of an immunoglobulin domain as the ligand of the target antigen means that recognition is not restricted to HLA antigens and that CAR-T cells are universally applicable as opposed to T cell receptor (TCR) transgenic T cells that recognize antigenic peptides presented in the context of a defined major histocompatibility complex (MHC), limiting clinical applications to subsets of patients with defined HLA typing. The intracellular domain is composed of the intracellular domain of the zeta chain of the CD3 component of the TCR, which will trigger signalling when the CAR engages the targeted ligand. The transmembrane region links the two extracellular and intracellular domains through the cell membrane and plays an important role in determining the conformation and flexibility of the CAR and its ability to efficiently bind the targeted antigen/epitope. Association of only these three functional domains characterized first generation CARs, as described in the original publications (Kuwana et al. 1987; Eshhar et al. 1993). However, full activation of T cells requires the addition of one (second generation CARs) or two (third generation CARs) domains from costimulatory molecules, such as CD28, 4-1BB/CD137, or OX40/CD134, that provide the T cell costimulatory signal. Currently approved CAR-T cells are second generation CAR-T cells; as an illustration, the CAR in tisagenlecleucel contains a 4-1BB domain, while the CAR in axicabtagene ciloleucel contains a CD28 domain. The nature of the costimulatory domain influences the ability of CAR-T cells to expand or persist (limit T cell exhaustion) in vivo after infusion into the patient, although it is unclear how this translates clinically and affects disease control, occurrence of adverse events, and overall survival due to the lack of head-to-head comparison between approved products. Finally, fourth generation CAR-T cells have been developed for preclinical projects. These cells, named armoured CAR cells or T cells redirected for universal cytokine-mediated killing (TRUCKS), encode not only a CAR (usually with one costimulatory domain, such as in second generation CARs) but also a cytokine, interleukin, pro-inflammatory ligand, or chemokine that will counteract the immune suppressive microenvironment that prevails in most solid tumours (Eshhar et al. 1993; Chmielewski and Abken 2015).

Pawlikowski, Maciej. "Minerals in Human Blood Vessels and Their Dissolution in Vitro." In Geology and Health. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195162042.003.0033.

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Cardiovascular disease knows no ethnic, national, or geographic boundaries. Men and women throughout the world can become affected by the obstruction of their arteries by cholesterol and the mineral hydroxylapatite (HA).This complex process leads to dysfunction of the arterial system and, because of the necessity of circulation of oxygenated blood, it also affects many tissues and organs. The whole process of occlusion (mineralization of the blood vessels), including precipitation and inorganic crystal formation, takes place in stages. The first stages are thought to involve cholesterol deposits (atherosclerotic plaque formation) in the interior of the vessel walls, or “intima,” as it is known. The formation of hydroylapatite, or “calcification,” begins with the attraction and localization of ions, mainly Ca2+ and PO43+, within the arteries. The vessels become altered and lose their suppleness, effectively interfering with their function as conduits for the blood (Pawlikowski 1986, 1991a,b, 1993, Pawlikowski et al. 1994). The initial stages of deposition can be detected with sensitive physical and chemical methods in vivo and with traditional laboratory methods and techniques on excised samples. In the mineralization stage, grains and crystals may become visible on heart valves as well as in the aortic tissue. (Pawlikowski and Pfitzner 1995,1999), and the new compounds can be identified using scanning electron microscopy and X-ray diffraction. Reasons for the destruction of tissues and the nucleation of minerals can be attributed to allodefects and autodefects. Autodefects in vessels are those attributable to abnormalities in the component tissues in the wall or pre-existing physical conditions. For example, at arterial bifurcations, intense local trauma from the flowing blood fluid might cause changes in those regions and attract cirulating ions. Autodefects are the result of reactions between biological tissues and foreign materials, such as small particles (dust) of all sorts, including bacteria or minerals that have been inhaled and travelled from the lungs via the blood into vessels throughout the body. Alternatively, allodefects may arise from poisons produced by bacteria and viruses during infections, or by other and various chemical products, such as food preservatives, that might be part of the circulating blood.

Dobson, C. M. "The Role of NMR Spectroscopy in Understanding How Proteins Fold." In Biological NMR Spectroscopy. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195094688.003.0014.

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Proteins are synthesized within the cell on ribosomes. Although there is debate as to the beginnings of folding, it is clear that the major events in the folding process of a protein occur following departure from the ribosome. Folding may involve a series of auxiliary proteins, including molecular chaperones, and for extracellular proteins may occur in part following secretion from the cell itself (Ellis, 1994). Nevertheless, many proteins also fold efficiently and correctly in isolation, for example, following transfer from a denaturing medium to a medium in which the native state is thermodynamically stable (Anfinsen, 1973). It seems most unlikely, given the improbability that folding could occur in a finite time on a random search basis (Levinthal, 1968), that the principles behind the folding process differ fundamentally in the two situations (in vivo and in vitro). Studies of the molecular basis of protein folding are therefore appropriately initiated in vitro, where physical techniques capable of providing detailed structural information can be used most readily and where folding of molecules can be examined in isolation (Evans and Radford, 1994). It has long been recognized that NMR spectroscopy, with its ability to define protein structure and dynamics in solution, is ideally suited as a technique for studying the structural transitions that take place during folding. The rapidity of folding of small proteins under most conditions, however, has until recently limited its direct application in ‘real time’ kinetic studies. Early applications of NMR in folding studies therefore included investigations of the equilibrium between folded and unfolded states, and a search for stable intermediate species (Jardetzky et al., 1972). This approach has in fact become very important in recent years with the discovery that a wide range of stable partially structured states can be generated under carefully chosen conditions, and with the development of heteronuclear NMR techniques that make possible their detailed characterisation (Dobson, 1994). The most famous of these partially folded states are known as ‘molten globules’, compact species with extensive secondary structure but Sacking persistent tertiary interactions; these are of particular interest as they appeal to be closely linked to intermediates observed in kinetic refolding experiments (Ptitsyn, 1995).

Kaplan, O., and J. S. Cohen. "Nuclear Magnetic Resonance Spectroscopy Studies of Cancer Cell Metabolism." In Biological NMR Spectroscopy. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195094688.003.0030.

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Nuclear magnetic resonance spectroscopy (NMR) is a powerful technique that provides information on biochemical status and physiological processes both in-vitro and in-vivo. The metabolism of intact cells and tissues can be studied in a continuous manner, and thus, NMR is a unique non-invasive research tool enabling detection of the metabolic changes as they occur (Cohen et al., 1983; Morris, 1988; Daly and Cohen, 1989). The first NMR study of cellular metabolism was done some 20 years ago, when Moon and Richards reported on the diphosphoglyceric acid (DPG) and pH shifts in erythrocytes (Moon, and Richards, 1973). NMR studies of metabolism of tumor cells were initiated by Navon et al. who investigated phosphorylated compounds in Ehrlich ascites cells (Navon etal., 1977). The choice of the element and isotope for a specific study of metabolism depends on its NMR properties, and the required data. The proton has the highest NMR sensitivity, and is the most abundant nucleus in biological molecules. However, this may cause difficulties in the interpretation and assignment of the 1H NMR spectrum. Moreover, since metabolic studies are usually performed in aqueous solutions, the huge signal from the water protons should be suppressed. Similarly, the wide signals arising from proteins and membrane components should be suppressed. These problems can be addressed now by several innovative NMR methods (Daniels et al., 1976; van Zijl and Cohen, 1992). The most widely used nucleus in NMR studies of metabolism has been 31p (see reviews Cohen (1988); Kaplan et al. (1992)). Phosphorous NMR spectroscopy can provide data on energy metabolism and substrate utilization, phospholipid pathways, precise intracellular pH, and membrane permeability and ion and water distribution. The spectrum is easy to interpret, but the number of compounds which are detectable is limited. Carbon NMR is also useful for NMR studies of metabolism since it is found in most biological compounds; however, 13C has a natural abundance of only 1.1%, and 13C enrichment is necessary. Other nuclei which are used less often in NMR studies of cellular metabolism are 23Na (Gupta et al., 1984), 19F (Malet-Martino, et al., 1986), and rarely 15N (Legerton et al., 1983) and 39K (Brophy et al., 1983).

"Fig. 12 Scanning electron micrograph of D.L-PLA nanoparticles loaded with CGP 57813. (Ref. 51.) scanning force microscopy (also called atomic force microscopy), enable the visualiza-tion of nanoparticles at atmospheric pressure without gold coating [12,64]. Neverthe-less, the resolution obtained with these new tools is still lower than that with SEM. For size determination, transmission electron microscopy is not as widely used as PCS and SEM, but it is still a powerful method for determining the morphology of particles. With this technique, Fessi et al. [42] estimated the wall thickness of PLA nanocapsules. Krause et al. [18] described the highly porous structure of PLA nano-spheres prepared by the emulsion-evaporation procedure. VIII. IN VITRO RELEASE STUDIES In vitro release studies should in principle be useful for quality control as well as for the prediction of in vivo kinetics. Unfortunately, due to the very small size of the par-ticles, the release rate observed in vivo can differ greatly from the release obtained in a buffer solution. However, in vitro release studies remain very useful for quality control as well as for evaluation of the influence of process parameters on the release rate of active compounds. In vitro drug release from microdispersed systems has been exten-sively reviewed by Washington [65]. Depending on the type of polyester, drug release from nanoparticles can take place through several processes, of which the following appear to be the most important: (1) The drug may diffuse out of the carrier through the solid matrix; to allow complete release from the carriers, (the concentration of drug in the release medium should re-main infinitely low, which condition is known as sink condition); (2) The solvent may penetrate the nanoparticles and dissolve the drug, which then diffuses out into the re-lease medium. Depending on the physico-chemical characteristics of the particles, wa-ter can enter the particles through narrow pores or by hydration. Once the drug is dis-solved, the drug diffuses out of the particles. Here again, since diffusion is driving the." In Pharmaceutical Dosage Forms, 204–16. CRC Press, 1998. http://dx.doi.org/10.1201/9781420000955-25.

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"THE EFFECT OF BLOOD TRANSFUSION ON IMMUNE FUNCTION Since homologous blood is never given to normal volunteers, the effect of blood transfusion on immune function in normal man is unknown. In patients who receive homologous blood, changes in immune response are evaluated in the context of the disease for which the blood is given and extrapolated to the effect of blood in the absence of disease. Changes in immunity consistently following transfusion for a variety of diseases can be assumed to be due to the transfusion and not to the diseases. Changes in immune function following transfusion with autologous blood or washed/filtered homologous blood can be compared to patients who are receiving routinely prepared homologous blood. The blood is given within the context of a surgical procedure as a consequence of operative blood loss which is due to trauma and trauma itself is associated with changes in immune function. In Vitro Lymphocyte Responsiveness Generally, inhibition of lymphocyte response to a given antigen or mitogen measured by incorporation of tritiated thymidine is accompanied by inhibition of response to all antigens and mitogens. Surgery, anesthesia, blood loss and blood transfusion cause lymphocyte suppression in clinical studies. Isolating the effect of homologous blood transfusion from the surgery, anesthesia and blood loss is not easy. In vitro lymphocyte responses decline in proportion to the magnitude of the procedure and in proportion to the amount of blood lost. Certain anesthetic agents, notably ether and cyclopropane, are associated with more profound suppression of immune function than halothane and nitrous oxide, for example (1). Patients with malignancies have low lymphocyte responses and declines with surgery are more precipitous than for patients without malignancies. Operated patients who receive homologus blood have declines in lymphocyte responsiveness compared to untransfused patients undergoing the same procedure. Thorough well-controlled studies have also observed the opposite, causing Munster et al. to comment that continued investigation " into the effect of PHA and ConA on post-traumatic lymphocyte transformation in many laboratories has produced no conclusive and repeatable pattern." (2) Prolonged depression in in vitro lymphocyte responsiveness is noted within hours of surgery and recovers over the next several days. The inhibition is due to both intrinsic and extrinsic factors since lymphocyte responsiveness can be partially restored by testing in plasma from normal blood donors. Homologous blood transfusion adds to the depressed state of the lymphocytes, but may cause stimulation in unoperated patients. The in vivo counterpart of in vitro testing of lymphocytes is delayed cutaneous hypersensitivity to antigens. Delayed Cutaneous Hypersensitivity There exists a correlation between in vivo and in vitro lymphocyte testing and preoperative evaluation of in vivo lymphocyte function is predictive of postoperative infection and subsequent course after surgery. Anergy is associated with low serum albumin and reduced polymophonuclear neutrophil chemotaxis. Patients with gastrointestinal bleeding, recipients of homologous blood, are often anergic (3). Sepsis following surgery for gastrointestinal bleeding is more common, hospital stay longer, and mortality higher in anergic patients. Patients who are initially anergic and remain anergic usually die." In Transfusion Immunology and Medicine, 292. CRC Press, 1995. http://dx.doi.org/10.1201/9781482273441-21.

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"These studies indicate that surgery depresses immune function because both anesthetic agents and physical trauma cause circulating levels of all lymphocyte subsets to decline after surgery with general anesthesia causing a panlymphocytopenia. Lymphocyte function, independent of cell number, is inhibited whether measured in vitro by lymphocyte responses to mitogens, antigens or homologous lymphocytes or measured in vivo by loss of response to skin testing. Lymphocyte functional inhibition may be related to disproportionate declines in T cell subsets or related to the appearance of immunosuppressive serum factors which inhibit lymphocytes. Transfusion potentiates whatever mechanism is responsible for lymphocyte inhibition; surgery accompanied by transfusion is followed by more profound decreases in lymphocyte numbers and in lymphocyte functional activity than surgery without transfusion. It is difficult to extrapolate these observations to retrospective clinical studies linking transfusion to increases in risk of infection or recurrence of malignancy. The study by Jensen et al.(9) suggests that use of leukocyte-free blood will prevent transfusion-associated adverse clinical phenomena, but this study needs to be replicated. The data certainly favors avoiding the use of homologous blood. BLOOD TRANSFUSION AND INFECTION The hypothesis that transfusion causes immune suppression leading to infections is confounded by the observation that the magnitude of the injury directly correlates with the degree of immune suppression and the necessity for transfusion. Potential confounders must be considered in any study of infections following surgery: confounders in one clinical situation are not significant or non-existent in another. Each field of surgery has its own risk factors for infection which are often associated with transfusion as well as with infection. The contribution of transfusion to the risk of infection independent of variables reflecting tissue destruction and bacterial contamination can be calculated statistically using stepwise logistic regression (13). This type of analysis is commonly used in medical studies, ignoring the basic precept that the independent variables must be truly independent. The independent variables are not genuinely independent: the magnitude of the procedure, the duration of surgery, the blood loss and the tissue damage are all related to one another and all are related to the number of units of blood given as well as to the risk of infection. The analysis is useful as long as one is aware that all conclusions drawn are subject to limitations. This analysis has been applied to 23 populations of patients undergoing procedures ranging from bone marrow harvesting to coronary artery bypass graft. In 22 studies transfusion was a statistically significant risk factor for infection and in 17 of the 23 it was the most significant determinant of infectious complications in stepwise logistic regression. In 14 studies the p value for the relationship between transfusion and infection was 0.001 or less. Non-operative site infections are increased following blood transfusion, indicating that transfusion's association with infection is independent of the operative trauma (14-16). Several studies have demonstrated a dose-response relationship between transfusion and infection risk but the greatest increment in risk is noted between no transfusion and one unit of blood (14,16-19). Transfusion is a potent predictor of infection after controlling for variables reflecting tissue destruction and contamination." In Transfusion Immunology and Medicine, 295. CRC Press, 1995. http://dx.doi.org/10.1201/9781482273441-24.

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Тези доповідей конференцій з теми "Etudes in vitro et in vivo":

Reeve, Amber N., Chadd W. Clary, Amit M. Mane, Kevin A. Dodd, and Lorin P. Maletksy. "Deep Knee Activities: In Vitro Kinematic Measurements to Compare With In Vivo Studies." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176662.

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Deep knee flexion is required for many activities of daily living during work, exercise, religious worship, and hobbies. Walker et al. [1] found that activities such as rising from a low chair or getting into or out of bath require between 100° and 160° of knee flexion. Other activities such as kneeling or squatting to pick an item off the ground can be difficult with a limited range of motion. Beside deep knee flexion being important for daily living activities, it is essential in non-Western cultures that commonly sit in deep knee-bending positions.

MAGNOL, Laetitia, Magali SAGE, Karine VUILLIER, Anne DRUILHE, and Séverine NADAUD. "L’utilisation des animaux en sciences : pourquoi et comment ?" In Les journées de l'interdisciplinarité 2022. Limoges: Université de Limoges, 2022. http://dx.doi.org/10.25965/lji.213.

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Pour progresser, la recherche en biologie animale s’appuie sur des données obtenues à partir de prélèvements faits sur des êtres vivants et sur différents modèles complémentaires. Ces modèles miment tout ou partie de l’être vivant étudié et reposent sur la modèlisation informatique (approche in silico), sur l’analyse de molécules en « tubes » et la culture de cellules ou de tissus (in vitro) et sur le recours aux animaux (in vivo). Les modèles in silico et in vitro sont très utilisés mais ne permettent pas, à l’heure actuelle, de reproduire la complexité d’un organisme vivant. L’utilisation des animaux en sciences reste d’actualité, et est menée dans un cadre juridique et éthique qui protège les animaux et exige le respect de leur bien-être. Dans les pages qui suivent, sont présentés le cadre européen actuellement en vigueur et les justifications de l’utilisation des animaux à des fins scientifiques au niveau international et au sein de l’établissement utilisateur d’animaux qu’est l’Université de Limoges.

Clary, Chadd W., Amit M. Mane, Amber N. Reeve, Kevin A. Dodd, and Lorin P. Maletsky. "Knee Kinematics During an In Vitro Simulated Deep Flexion Squat." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176683.

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Understanding the behavior of the natural knee in deep flexion can offer insight into the necessary design characteristics of a total knee implant. Andriacchi et al. [1] measured the in vivo characteristics of knee motion down to ∼150° knee flexion during a weight bearing squat. Likewise, Li et al. [2] investigated deep knee flexion in vitro using robotic technology during passive knee flexion. Both of these studies offer insight into the behavior of the knee in deep knee flexion; however, they have some limitations with regards to assessing physiological activities in a controlled manner. The purpose of this study was to measure the kinematics of the knee during a simulated in vitro deep knee squat so that in the future a dynamic, load-bearing, simulated deep knee squat could be used as a tool in the design of total knee prostheses.

Makris, P. E., A. Papadopoulos, and D. A. Tsakiris. "LIPOXYGENASE PRODUCTS CHANGES IN ‘IN VITRO’ AND ‘IN VIVO’ ASPIRINISED PLATELETS UNDER THE INFLUENCE OF PAF AND EPINEPHRINE." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644829.

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We aimed to investigate the changes of lipoxygenase products in platelets and the simultaneous behaviour of ‘in vivo’ or ‘in vitro’ aspirinised platelets, stimulated by two agonists, PAF and epinephrine (EPI). 12 healthy were included. 6 received 20mg of aspirin (ASA) per os for 7 days (group A), and in 6 (group B) platelets were aspirinised ‘in vitro’ (5 or lOmin incubation at 37°C with ASA 1M). In group A blood was drawn once at the beginning and once at the end of the trial, while in group B just ome. First, platelet aggregation was studied using two agonists simultaneously (0.6 ¼M EPI and 20 nM PAF). We incubated then all platelet samples with 0.5 M of the substance BW755C (kind offer of Dr Moncada) far 3 min at 37°C. Second we measured PL0 products according to Takayama et al (1980), in platelets with or without ASA, and in platelets with ASA and after treatment with BW755C, always after addition of both agonists. Our results showed: a) Irreversible aggregation was slightly enhanced by the simultaneous addition of PAF and EPI in both groups and in non-aspirinised platelets. After ASA treatment, each agonist alone did not induce irreversible aggregation, whereas their combination overcame this inhibition, a fact not noticed under BW755C (a known PLO inhibitor). b) PLO products were measured in nmol TBRS/10 platelets:Our results agree with Cerletti et al (1986) and confirm that the two agonists combined are capable of overcoming the inhibition caused by ASA, possibly by activating the PLO pathway (Cerletti et al, 1986). Respectively the quantitative determination of PLO products (about which we did not notice any other report insofar) confirm the above assumption, since inhibition by BW755C coincides with the steep fall of PLOlevels, which for group A is statisticallysignificant (p≺0.01, paired t-test) and for group B entirely significant (p ≺0.001).

Reymond, Philippe, Yvette Bohraus, Fabienne Perren, and Nikos Stergiopulos. "Validation of a Person Specific 1D Model of the Systemic Arterial Tree." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-206424.

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The aim of this study is to validate a person-specific distributed model of the main systemic arterial tree. This model is built and validated with non-invasive measurements on the same person, leading therefore to a coherent set of physiological data. One-dimensional (1D) models have been used for more than 30 years to predict or analyze pressure and flow in the arterial tree (Avolio [1], Stergiopulos et al [2], Westerhof et al [3]), demonstrating their aptitude of modeling wave propagation, however, they have never being validated using in vivo measurements. A quantitative validation was performed in vitro in an elastic tube network dimensioned to resemble the human arterial tree by Matthys et al. [4]. The results were supportive of the 1D model’s capacity to yield good predictions, however, neither the form of the waves nor the elastic properties of the in vitro tube network were matching faithfully their physiological counterparts, so the interest to quantitatively validate the 1D model in vivo remained.

Roy, Abhijit Sinha, Lloyd H. Back, Ronald W. Millard, Saeb Khoury, and Rupak K. Banerjee. "In Vitro Pressure Flow Relationship in Model of Significant Coronary Artery Stenosis." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61657.

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Simultaneous measurement of pressure and flow rate has been found to be helpful in evaluating the physiologic significance of obstructive coronary artery disease and in the diagnosis of microvascular disease. This experimental study seeks to find important pressure-flow relationship in an in-vitro model of significant coronary artery stenoses using a non-Newtonian liquid, similar to blood showing a shear thinning behavior, using significant stenotic in-vitro model (minimal area stenosis = 90%). The geometry for the stenotic model is based on data provided in an in vivo study by Wilson et al., (1988). For 90% area stenosis, the maximum recorded pressure drop for steady flow rate of 55, 79 and 89 are 14, ~24 and ~32 mmHg respectively. The maximum pressure drop at flow rate of 115 ml/min (the physiological limit) is 50.3 mmHg respectively. Using a power law curve fit, the maximum pressure drop (in mmHg) related with flow rate (in ml/min) provided a power law index of 1.72. Shorter distal length than required in the in-vitro model did not allow the recording of complete pressure recovery. This preliminary data provides reference values for further experimentation both in vitro with pulsatile flow as in physiological conditions, and in vivo.

Wang, James H. C., David Stone, Fengyan Jia, Chris Celechovsky, and Savio L. Y. Woo. "Biological Responses of Fibroblasts to Cyclic Stretching: A Novel Culture Model Study." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-2573.

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Abstract Because of the advantage of better control of experimental conditions, in vitro model systems have been developed to examine the effects of mechanical loading on cells. Previous studies have shown that cyclic stretching causes cells to change orientation, proliferation and gene expression (Buck et al., 1980; Wang et al., 1995; Leung et al., 1976). However, one drawback of these model systems is that they are unable to control cell alignment and shape, and in addition, some provide heterogeneous strains to cells during stretching (See review by Schaffer, 1994). Consequently, cellular responses in these systems may not be similar to those in vivo. For example, tendon and ligament fibroblasts align with collagen fibers in vivo and are hence subjected to stretching along the tissue long axis. In contrast, in many existing systems, cells either randomly orient or orient away from the stretching direction.

Owen, John R., and Jennifer S. Wayne. "Finite Element Modeling of Repair Cartilage Beneath a Protective Layer." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-42923.

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Significant efforts are being devoted to the creation of replacement tissue for repair of defects in articular surfaces. Some success has been realized; yet, the normal zonal characterstics of articular cartilage throughout its thickness and normal material properties have not been reproduced in vitro in scaffolds nor in vivo in repairing defects. The fate of such transplanted scaffolds in vivo may be doomed mechanically from the outset if material properties of sufficient quality are not developed. The superficial tangential zone (STZ) has been shown to play a critical role in supporting axial loads and retaining fluids (Glazer and Putz, 2002, Torzilli, et al, 1983, Torzilli, 1993). Previous models have demonstrated excessive axial deformation of repair cartilage without the STZ (Smith, et al 2001, Wayne, et al, 1991) Additionally, modeling the STZ of normal cartilage as transversely isotropic has yielded better agreement with indentation experimental results than isotropic models (Korhonen, et al, 2002, Mow, et al, 2000, Cohen, et al, 1993). This study uses finite element analysis to model the STZ with a preferred direction parallel to the articulating surface, thereby simulating a “split-line” direction. The in-plane directions are modeled normal to the “split-line” direction and the articulating surface. Normal and repairing defects are modeled with the importance of the STZ emphasized.

Kaufman, Randal J., Debra D. Pittman, Louise C. Wasley, W. Barry Foster, Godfrey W. Amphlett, and Alan R. Giles. "DIRECTED MUTAGENESIS IN THE STUDY OF THE REQUIREMENTS FOR FACTOR VIII ACTIVITY IN VITRO AND IN VIVO." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644769.

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Factor VIII is a high molecular weight plasma glycoprotein that functions in the blood clotting cascade as the cofactor for factor DCa proteolytic activation of factor X. Factor VIII does not function proteolytically in this reaction hut itself can be proteolytically activated by other coagulation enzymes such as factor Xa and thrombin. In the plasma, factor VIII exists as a 200 kDa amino-terminal fragment in a metal ion stabilized complex with a 76 kDa carboxy-terminal fragment. The isolation of the cENA for human factor VIII provided the deduced primary amino acid sequence of factor VIIT and revealed three distinct structural domains: 1) a triplicated A domain of 330 amino acids which has homology to ceruloplasmin, a plasma copper binding protein, 2) a duplicated C domain of 150 amino acids, and 3) a unique B domain of 980 amino acids. These domains are arranged as shown below. We have previously reported the B domain is dispensible far cofactor activity in vitro (Toole et al. 1986 Proc. Natl. Acad 5939). The in vivo efficacy of factor VIII molecules harboring the B domain deletion was tested by purification of the wildtype and modified forms and infusion into factor VIII deficient, hemophilic, dogs. The wildtype and the deleted forms of recombinant derived factor VIII exhibited very similar survival curves (Tl/2 = 13 hrs) and the cuticle bleeding times suggested that both preparations appeared functionally equivalent. Sepharose 4B chromatography indicated that both factor VIII molecules were capable of binding canine plasma vWF.Further studies have addressed what cleavages are necessary for activation of factor VIII. The position of the thrombin, factor Xa, and activated protein C (AFC) cleavage sites within factor VIII are presented below, site-directed ENA medicated mutagenesis has been performed to modify the arginine at the amino side of each cleavagesite to an soleucine. In all cases this modification resulted in molecules that were resistant to cleavage by thrombin at the modified site. Modification of the thrombin cleavage sites at 336 and 740 and modification of the factor Xa cleavage site at 1721 resulted in no loss of cofactor activity. Modification of the thrombin cleavage site at either 372 or 1689 destroyed oofactor activity. Modification of the thrombin cleavage site at 336 resulted in a factor VIII having an increased activity, possibly due to resistance to inactivation. These results suggest the requirement of cleavage at residues 372 and 1689 for cofactor activity.

Klisch, Stephen M., Suzanne E. Holtrichter, Robert L. Sah, and Andrew Davol. "A Bimodular Second-Order Orthotropic Stress Constitutive Equation for Cartilage." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-59475.

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The design of tissue-engineered constructs grown in vitro is a promising treatment strategy for degenerated cartilaginous tissues. Cartilaginous tissues such as articular cartilage and the annulus fibrosus are collagen fiber-reinforced composites that exhibit orthotropic behavior and highly asymmetric tensile-compressive responses. They also experience finite deformations in vivo. Successful integration with surrounding tissue upon implantation likely will require cartilage constructs to have similar structural and functional properties as native tissue. Reliable stress constitutive equations that accurately characterize the tissue’s mechanical properties must be developed to achieve this aim. Recent studies have successfully implemented bimodular theories for infinitesimal strains (Soltz et al., 2000; Wang et al., 2003); those models were based on the theory of Curnier et al. (1995).

Звіти організацій з теми "Etudes in vitro et in vivo":

Schuster, Gadi, and David Stern. Integrated Studies of Chloroplast Ribonucleases. United States Department of Agriculture, September 2011. http://dx.doi.org/10.32747/2011.7697125.bard.

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Gene regulation at the RNA level encompasses multiple mechanisms in prokaryotes and eukaryotes, including splicing, editing, endo- and exonucleolytic cleavage, and various phenomena related to small or interfering RNAs. Ribonucleases are key players in nearly all of these post-transcriptional mechanisms, as the catalytic agents. This proposal continued BARD-funded research into ribonuclease activities in the chloroplast, where RNase mutation or deficiency can cause metabolic defects and is often associated with plant chlorosis, embryo or seedling lethality, and/or failure to tolerate nutrient stress. The first objective of this proposal was to examined a series of point mutations in the PNPase enzyme of Arabidopsis both in vivo and in vitro. This goal is related to structure-function analysis of an enzyme whose importance in many cellular processes in prokaryotes and eukaryotes has only begun to be uncovered. PNPase substrates are mostly generated by endonucleolytic cleavages for which the catalytic enzymes remain poorly described. The second objective of the proposal was to examine two candidate enzymes, RNase E and RNase J. RNase E is well-described in bacteria but its function in plants was still unknown. We hypothesized it catalyzes endonucleolytic cleavages in both RNA maturation and decay. RNase J was recently discovered in bacteria but like RNase E, its function in plants had yet to be explored. The results of this work are described in the scientific manuscripts attached to this report. We have completed the first objective of characterizing in detail TILLING mutants of PNPase Arabidopsis plants and in parallel introducing the same amino acids changes in the protein and characterize the properties of the modified proteins in vitro. This study defined the roles for both RNase PH core domains in polyadenylation, RNA 3’-end maturation and intron degradation. The results are described in the collaborative scientific manuscript (Germain et al 2011). The second part of the project aimed at the characterization of the two endoribonucleases, RNase E and RNase J, also in this case, in vivo and in vitro. Our results described the limited role of RNase E as compared to the pronounced one of RNase J in the elimination of antisense transcripts in the chloroplast (Schein et al 2008; Sharwood et al 2011). In addition, we characterized polyadenylation in the chloroplast of the green alga Chlamydomonas reinhardtii, and in Arabidopsis (Zimmer et al 2009). Our long term collaboration enabling in vivo and in vitro analysis, capturing the expertise of the two collaborating laboratories, has resulted in a biologically significant correlation of biochemical and in planta results for conserved and indispensable ribonucleases. These new insights into chloroplast gene regulation will ultimately support plant improvement for agriculture.