Academic literature on the topic 'Cellule vive'
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Journal articles on the topic "Cellule vive"
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Farhat, Raed, Ayman El-Seedy, Kamal El-Moussaoui, Marie-Claude Pasquet, Catherine Adolphe, Eric Bieth, Jeanne Languepin, Isabelle Sermet-Gaudelus, Alain Kitzis, and Véronique Ladevèze. "Multi-physiopathological consequences of the c.1392G>T CFTR mutation revealed by clinical and cellular investigations." Biochemistry and Cell Biology 93, no. 1 (February 2015): 28–37. http://dx.doi.org/10.1139/bcb-2014-0042.
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This study combines a clinical approach and multiple level cellular analyses to determine the physiopathological consequences of the c.1392G>T (p.Lys464Asn) CFTR exon 10 mutation, detected in a CF patient with a frameshift deletion in trans and a TG(11)T(5) in cis. Minigene experiment, with different TG(m)T(n) alleles, and nasal cell mRNA extracts were used to study the impact of c.1392G>T on splicing in both in cellulo and in vivo studies. The processing and localization of p.Lys464Asn protein were evaluated, in cellulo, by western blotting analyses and confocal microscopy. Clinical and channel exploration tests were performed on the patient to determine the exact CF phenotype profile and the CFTR chloride transport activity. c.1392G>T affects exon 10 splicing by inducing its complete deletion and encoding a frameshift transcript. The polymorphism TG(11)T(5) aggravates the effects of this mutation on aberrant splicing. Analysis of mRNA obtained from parental airway epithelial cells confirmed these in cellulo results. At the protein level the p.Lys464Asn protein showed neither maturated form nor membrane localization. Furthermore, the in vivo channel tests confirmed the absence of CFTR activity. Thus, the c.1392G>T mutation alone or in association with the TG repeats and the poly T tract revealed obvious impacts on splicing and CFTR protein processing and functionality. The c.[T(5); 1392G>T] complex allele contributes to the CF phenotype by affecting splicing and inducing a severe misprocessing defect. These results demonstrate that the classical CFTR mutations classification is not sufficient: in vivo and in cellulo studies of a possible complex allele in a patient are required to provide correct CFTR mutation classification, adequate medical counseling, and adapted therapeutic strategies.
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Sheng, Guojun. "Vive la difference." Cell Adhesion & Migration 4, no. 3 (July 2010): 439. http://dx.doi.org/10.4161/cam.4.3.12642.
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Wong, RaymondChing-Bong, and Tu Nguyen. "Neuroregeneration using in vivo cellular reprogramming." Neural Regeneration Research 12, no. 7 (2017): 1073. http://dx.doi.org/10.4103/1673-5374.211182.
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Peng, Tao, and Howard C. Hang. "SORTing out cellular proteomes in vivo." Nature Biotechnology 32, no. 5 (May 2014): 445–46. http://dx.doi.org/10.1038/nbt.2898.
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Trani, Jose L., Howard K. Song, Susan M. Lerner, Hooman Noorchashm, Joseph W. Markmann, Jing Wang, Clyde F. Barker, Ali Naji, and James F. Markmann. "IN VIVO CHARACTERIZATION OF CELLULAR XENOIMMUNITY." Transplantation 67, no. 9 (May 1999): S554. http://dx.doi.org/10.1097/00007890-199905150-00072.
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Modo, Michel, Mathias Hoehn, and Jeff W. M. Bulte. "Cellular MR Imaging." Molecular Imaging 4, no. 3 (July 1, 2005): 153535002005051. http://dx.doi.org/10.1162/15353500200505145.
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Cellular MR imaging is a young field that aims to visualize targeted cells in living organisms. In order to provide a different signal intensity of the targeted cell, they are either labeled with MR contrast agents in vivo or prelabeled in vitro. Either (ultrasmall) superparamagnetic iron oxide [(U)SPIO] particles or (polymeric) paramagnetic chelates can be used for this purpose. For in vivo cellular labeling, Gd3+- and Mn2+- chelates have mainly been used for targeted hepatobiliary imaging, and (U)SPIO-based cellular imaging has been focused on imaging of macrophage activity. Several of these magneto-pharmaceuticals have been FDA-approved or are in late-phase clinical trials. As for prelabeling of cells in vitro, a challenge has been to induce a sufficient uptake of contrast agents into nonphagocytic cells, without affecting normal cellular function. It appears that this issue has now largely been resolved, leading to an active research on monitoring the cellular biodistribution in vivo following transplantation or transfusion of these cells, including cell migration and trafficking. New applications of cellular MR imaging will be directed, for instance, towards our understanding of hematopoietic (immune) cell trafficking and of novel guided (stem) cell-based therapies aimed to be translated to the clinic in the future.
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Boppart, Stephan A., Brett E. Bouma, Costas Pitris, James F. Southern, Mark E. Brezinski, and James G. Fujimoto. "In vivo cellular optical coherence tomography imaging." Nature Medicine 4, no. 7 (July 1998): 861–65. http://dx.doi.org/10.1038/nm0798-861.
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Rice, Andrew P., and Jason T. Kimata. "Cellular cofactors and HIV-1 infectionin vivo." Future Virology 1, no. 3 (May 2006): 337–47. http://dx.doi.org/10.2217/17460794.1.3.337.
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Hornsby, P. J. "Cellular Senescence and Tissue Aging In Vivo." Journals of Gerontology Series A: Biological Sciences and Medical Sciences 57, no. 7 (July 1, 2002): B251—B256. http://dx.doi.org/10.1093/gerona/57.7.b251.
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Tréton, J. A. "Cellular aging, in vitro and in vivo." Aging Clinical and Experimental Research 5, no. 4 (August 1993): 291–97. http://dx.doi.org/10.1007/bf03324177.
Full textDissertations / Theses on the topic "Cellule vive"
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Mitri, Elisa. "Fabrication of microfluidic devices for studying living cells responding to external stimuli by FTIR vibrational spectroscopy." Doctoral thesis, Università degli studi di Trieste, 2014. http://hdl.handle.net/10077/9971.
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2012/2013The present PhD Thesis is about the development of new fabricative strategies to obtain microfluidic devices suitable for InfraRed MicroSpectroscopy (IRMS) studies on living cells in physiological environment and the demonstration of the screening and diagnostic capabilities of this technique for bio-medical applications. IRMS detects the vibrational pattern of molecules allowing the label-free characterization of the chemical profile of a biological specimen and its correlation with the sample morphology. Although powerful and versatile, this technique has been limited until recent years to the study of fixed or dried samples, in order to bypass the problem of water absorptions in the infrared spectral region. The use of microfabrication techniques for the production of Visible-Infrared (Vis-IR) transparent devices has recently opened an innovative approach, able to release some of the constrains encountered when dealing with living cells. Moreover, microfabrication is the best option to achieve long-range reproducibility of the optical path, which is mandatory for an accurate water subtraction in order to disclose cellular IR features. At first, we aimed to develop an IR-Vis transparent microfluidic chip with long-time stability in experimental conditions. The optical transparency was granted by the use of CaF2 or BaF2 as substrates, but their low surface energies imposed a challenge in order to establish reliable microfabrication protocols. With the introduction of a new strategy, that we refer to as “silicon-like”, based on the sputtering of a thin silicon layer onto the IR materials, it was possible to modify the surface properties of the substrates without changing their optical properties. These new substrates allowed the use of several common photo-resists as structural materials. The epoxy-based negative tone SU-8 was chosen for its chemical properties (resistance to solvents and watery media) and its long-term stability in experimental conditions. We established a new sealing protocol exploiting the optical properties of SU-8, able to create a chemical bonding between two already patterned layers of the polymer. It was thus possible to produce a new generation of fluidic chips, characterized by broadband transparency from mid-IR to UV and long-term stability in continuous flow conditions. Subsequently, the devices were employed to perform IRMS measurements on both adherent and circulating cells. In particular, we characterize the spectroscopic features associated to each stage of B16 cell cycle, the changes undergone in living MCF-7 upon exposure to hypo-osmotic and thermal stress and the apoptosis progression of U-937 cells, induced by growth factors removal and CCCP (Carbonyl Cyanide m-Chloro Phenylhydrazone) stimulation. All the studies had the intent to further verify the effectiveness of the microfluidic approach for both circulating and adherent living cells analysis and to prove the capabilities of IRMS as tool for the observation of biochemical processes undergone by live beings. For this reason, to validate the achieved results, a parallel analysis with a well established analytical technique such as the flow-cytometry was performed. The present Thesis demonstrates the capabilities of IRMS coupled with microfluidic technologies, as a diagnostic tool for bio-medical investigation of bio-medical applications. Thanks to the precise control of the cellular microenvironment, as well as its flexibility in terms of experimental design, IRMS could be seen as a new promising frontier for modern biology.
La presente tesi di dottorato concerne lo sviluppo di nuove strategie fabricative, volte all’ottenimento di dispositivi microfluidici per lo studio di cellule vive, in condizioni fisiologiche, tramite MicroSpettroscopia InfraRossa (MSIR). Inoltre intende dimostrare le potenzialità di questa tecnica analitica come mezzo di screening diagnostico in ambito bio-medico. La MSIR prevede la caratterizzazione di bio-molecole tramite l’acquisizione del loro spettro vibrazionale. A tale spettro viene poi associata un’immagine ottica, ottenendo quindi la correlazione tra il profilo morfologico di un campione e il suo contenuto chimico. Inoltre, l’uso della spettroscopia infrarossa permette una diretta analisi del campione senza l’uso di marcatori esterni o protocolli di fissazione. L’utilizzo di questa tecnica, sebbene molto potente e versatile, fino a pochi anni fa è stato limitato a campioni fissati o deidratati al fine di aggirare i problemi derivanti dal forte assorbimento delle molecole d’acqua nell’infrarosso, noti come “barriera di assorbimento dell’acqua”. L’utilizzo di tecniche di micro fabbricazione per la realizzazione di dispositivi trasparenti nelle regioni del visibile e dell’infrarosso ha permesso di sviluppare un nuovo e innovativo approccio allo studio di campioni biologici tramite MSIR, superando le limitazioni connesse alla “barriera di assorbimento dell’acqua” e quindi alla manipolazione di sistemi viventi. Inoltre, l’approccio micro fabbricativo è la migliore strategia per ottenere una perfetta riproducibilità del cammino ottico, necessaria per sottrarre dallo spettro vibrazionale il contributo dell’acqua e ricavare quindi le caratteristiche spettrali delle cellule. Nella parte iniziale di questo lavoro di tesi, si è rivolta particolare attenzione allo sviluppo di nuovi dispositivi microfluidici trasparenti nel visibile e nell’infrarosso caratterizzati da una lunga stabilità nelle condizioni di misura. I substrati comunemente usati nella MSIR (fluoruro di calcio o bario, CaF2 e BaF2 rispettivamente) hanno una bassa energia superficiale che richiede lo sviluppo di nuovi protocolli fabbricativi per l’ottenimento dei dispositivi. Durante questo lavoro è stata proposta una nuova strategia operativa, chiamata “silicon-like”, che prevede la modifica delle proprietà superficiali dei materiali tramite la deposizione di un sottile strato di silicio sulle finestre ottiche. Lo strato di silicio provoca un incremento dell’energia superficiale del substrato senza alterarne le proprietà ottiche e permette l’uso dei comuni resist come materiali strutturali. Tra questi, si è deciso di utilizzare l’SU-8 una resina epossidica con tono negativo le cui proprietà chimico-fisiche (resistenza ai solventi e all’ambiente acquoso) e la sua stabilità nel tempo soddisfano i requisiti imposti dalle condizioni di misura. Infine è stato sviluppato un nuovo protocollo di chiusura per i dispositivi, sfruttando le proprietà ottiche dell’SU-8. Grazie a queste innovazioni è stato possibile sviluppare una nuova generazione di dispositivi microfluidici dotati di grande stabilità nel tempo e ottima trasparenza nelle regioni del visibile e infrarosso. Successivamente i dispositivi sono stati impiegati per condurre diversi studi sia su cellule circolanti che in adesione tramite MSIR. Nello specifico, sono state caratterizzate le caratteristiche spettrali che distinguono ciascuna fase del ciclo cellulare per le cellule B16, i cambiamenti nel contenuto chimico di cellule MCF-7 indotte da stress di tipo termico e osmotico e i riarrangiamenti cellulari subiti dai monociti (U937) durante la progressione attraverso l’apoptosi. Tutti questi studi avevano l’intento di dimostrare l’utilità dell’approccio microfluidico allo studio di cellule vive tramite MSIR e validare le potenzialità della MSIR come tecnica di indagine diagnostica per i processi biochimici in vivo. Per questo, parallelamente agli esperimenti MSIR sono stati condotti degli esperimenti di citofluorimetria, una tecnica di routine in ambito biologico. Questa tesi dimostra le potenzialità della MSIR accoppiata alla microfluidica come mezzo di indagine bio-medica. Grazie al preciso controllo dell’ambiente cellulare e alla flessibilità ottenibile in termini di design degli esperimenti MSIR può essere vista come una nuova frontiera per la biologia moderna.
XXVI Ciclo
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El, Ouali Hassan. "Détection immunocytochimique de la laminine in vivo et in vitro au niveau du tube séminifère de rat au cours de l'ontogenèse." Nancy 1, 1990. http://www.theses.fr/1990NAN10545.
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Zucchini, Nicolas. "Etude in vivo des cellules dendritiques plasmacytoïdes murines à l'infection par le cytomégalovirus murin." Aix-Marseille 2, 2009. http://theses.univ-amu.fr.lama.univ-amu.fr/2009AIX22090.pdf.
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Les cellules dendritiques plasmacytoïdes (pDC) sont caractérisés par leur habilité à produire rapidement de forts taux d'interféron de type I (IFN-I) en réponse à de nombreux virus, notamment lors de l'infection in vivo par le cytomégalovirus murin (MCMV). Les pDC contribuent aussi à la production d'autres cytokines. Cependant, leur relative contribution pour ces fonctions comparées à d'autres celliles n'est pas clairement établie. En outre, le rôle global des pDC dnas la réistance de l'hôte à l'infection virale est difficile à étudier avec rigueur, en partie en raison de l'absence d'une méthode permettant la déplétion efficace et spécifique de ces cellules in vivo. Les expressions de l'IFN-I, de l'IL-2 et du TNF-a ont été examinées par cytométrie en flux multiparamétrique permettant d'identifier les sources cellulaires et les mécanismes molléculaires impliqués pour la production de ce cytokines innées dans divers tissus précocement après l'infection par le MCMV. Les pDC spléniques sont la principale source de cytokines innées précocement après l'infection par le MCMV, avec production simultanée de trois cytokines dans des cellules individuelles. De plus, un rôle redondant de TLR-7 et -9 a été identifié pour la régulation de ces fonctions. Dans le but d'obtenir différents modèles murins conçus pour permettre l'étude rigoureuse des fonctions des pDC, nous sommes sur le point de générer des souris qui exprimeront spécifiquement la recombinase CRE dans les pDCPlasmacytoid dentritic cells (pDC) are characterized by their ability to rapidly produce high levels of type I interferon (IFN-I) in response to many viruses, especially during in vivo infection by murine cytomegalovirus (MCMV). PDC also contribute to the production of other cytokines. However, their relativecontribution to these functions compared to other cells in unclear. In addtition, the overall role of pDC in the host resistance to viral infection is difficult to study rigorously, partly beacause of the lack beacause of a method for the effective and specific depletion of these cells in vivo. The expressions of IFN-I, IL-2 and TNF-a were examined by multiparameter flow cytometry identify the cellular souces and molecular mechanisms involved in the production if innate cytokines in various tissues early after infection by MCMV. Splenic pDC are the main source of innate cytokines early after infection been identified to regulate these functions. In order to obtain different mouse models designed for the rigorous study of pDC functions, we are about to generate mice that express CRE recombinase specifically in pDC
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Kasprzyk, Laetitia. "Caractérisation du facteur de transmission ZBTB4 in vivo & in vitro." Paris 7, 2013. http://www.theses.fr/2013PA077098.
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Les facteurs de transcription de la famille des ZBTBs jouent un rôle important dans l'organisme. Ces facteurs sont en effet impliqués dans le développement, ainsi que dans des processus pouvant conduire à la tumorigenèse. Trois de ces facteurs EBTB, nommés Kaiso, ZBTB4 et ZBTB38, appartiennent également à une famille de protéines capables de lier l'ADN méthylé (MBP) et qui sont de même impliquées dans des mécanismes cellulaires essentiels. Le but de ma thèse était d'initier la caractérisation de l'une de ces protéines ZBTB-MBP, ZBTB4, via la génération d'un modèle murin. Les premiers résultats sur l'étude du phénotype de ces souris, portant une mutation inhibitrice du gène Zbtb4, ont montré que les souris sont viables, fertiles, mais présentent un poids plus faible au niveau global, ainsi qu'au niveau de trois organes : le cerveau, le coeur et les reins. Elles montrent également un trouble du comportement avec une tendance accrue à l'anxiété. En parallèle de cette approche in vivo, l'étude in vitro de ZBTB4 a montré des résultats en faveur d'un rôle suppresseur de tumeur. Ce travail pourrait donc donner des pistes quant au rôle de ZBTB4 dans l'organismeThe ZBTBs transcription factors play an important role in the organism. These factors are indeed involved in development, as well as in several processes that may lead to tumorigenesis. Three of these ZBTB factors, named Kaiso, ZBTB4 and ZBTB38, also belong to a protein family able to bind methylated DNA (MBP) and also implicated in essential cellular mechanisms. The goal of my graduate work was to initiate the characterization of one of these ZBTB-MBP protein, ZBTB4, by generating a mouse model. The preliminary results on the study of the mice phenotype, carrying an inhibitory mutation of the Zbtb4 gene, showed that the mice are viable, fertile, but display an overall lower weight, especially for three organs in particular : the brain, the heart and the kidneys. They also display a behavior trouble, with an increased tendency to anxiety. In parallel of this in vivo approach, an in vitro study of ZBTB4 showed results in favor to a tumor suppressor role. This work could thus give clues concerning the role of ZBTB4 in the organism
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Breart, Béatrice. "Caractérisation du comportement des cellules NK in vivo." Nice, 2005. http://www.theses.fr/2005NICE4042.
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Les cellules " natural killer " (nk) sont des acteurs majeurs de l'immunite innee. Toutefois, encore peu de donnees nous permettent de comprendre leur role au sein du systeme immunitaire et notamment leurs mecanismes d'action et les partenaires cellulaires avec lesquels elles interagissent. Au cours de cette these nous avons etudie le comportement des cellules nk in vivo au cours de l'infection par le parasite intracellulaire leishmania major. Dans un premier temps, nous avons montre que les cellules nk sont, en premier lieu, recrutees dans le ganglion drainant ou elles sont activees et produisent de l'interferon-g (ifn-g), par un mecanisme impliquant les cellules cd4+, pour etre ensuite detectees au site de lesion trois jours apres infection. Nous avons aussi montré que les cellules nk, de faible mobilité, sont situees a l'endroit cle d'initiation de la reponse adaptative, au contact des dc, avec lesquelles elles interagissent, et des lymphocytes t, ce qui suggere qu'elles ont un role actif dans le controle des reponses immunitaires. Enfin, nous avons mis en evidence une nouvelle population de cellules exprimant a la fois le marqueur classique des dc, cd11c, et le marqueur des cellules nk, cd49b. Cette population constitue en fait une sous-population de cellules nk qui, par leur recrutement et leur activite, se comporte comme les cellules nk cd11c- au cours de l'infection par l. Major. Pris dans leur ensemble, nos resultats identifient pour la premiere fois une interaction in vivo entre les cellules nk et les dc, et constituent un prerequis necessaire a la poursuite des etudes sur ces cellules in vivoNatural killer (nk) cells are major actor of innate immunity, however their role in the immune system as their mechanism of activation and their cellular interactions are still poorly understood. During this ph. D, we have studied the nk cell behavior in course of the intracellular parasite leishmania major infection. Primary we have shown that, after parasite inoculation, nk cells are first recruited in the draining lymph node where they are activated and produce ifn-g, by a mechanism involving cd4+ cells, and are then detected in the lesion site three days after infection. We have also schown that nk cells, low motile cells, are localized in a strategic area of the lymph node, where the initiation of adaptativ immune response takes place, in close contact and in interaction with dc and t lymphocytes. These data suggest that nk cells have an activ role in the control of immune response. Finally we caracterize a new cell population which express classical marker of dc, cd11c and the nk cell marker, cd49b. This population is in fact a sub-population of nk cells which, in term of recruitment and activity, behave as nk cd11c-nk cells in course of l. Majors infection. In conclusion, our results identify, for the first time, an interaction in vivo between nk cell and dc and constitute a necessary prelude of further nk cell study in vivo
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Maamar, Hédia. "Etude in vivo du système cellulolytique de Clostridium cellulolyticum : caractérisation du premier mutant d'insertion cipC." Aix-Marseille 1, 2003. http://www.theses.fr/2003AIX11034.
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La bactérie anaérobie Clostridium cellulolyticum, produit des complexes multiprotéiques (cellulosomes) qui dégradent la cellulose. Ces complexes sont composés de plusieurs enzymes ancrées sur une protéine d'assemblage (CipC). La plupart des gènes codant pour les sous unités des cellulosomes sont groupés dans un cluster de 26 kb. Deux mutants spontanés d'insertion du gène cipC (1er gène du cluster) ont été obtenus. CipC est interrompu par une seule séquence d'insertion (IS) (ISCce1) dans un cas ou par deux ISs (ISCce1 interrompue par ISCce2) dans l'autre cas. ISCce2 a été classée dans la famille des IS256, alors que ISCce1 pourrait être le premier membre d'une nouvelle famille d'IS. L'insertion dans cipC affecte la synthèse des cellulosomes et la capacité de la souche à dégrader la cellulose cristalline. Le mutant produit une protéine cipC tronquée et assemble des complexes qui n'incluent aucune des enzymes codées par les gènes du cluster. Ces complexes contiennent au moins 12 protéines à dockérine dont la majorité sont inconnues. Le mutant produit également 3 protéines majoritaires inconnues ne faisant pas partie des cellulosomes. La complémentation d'un mutant par clonage du gène cipC n'a pas permis de restaurer le phénotype sauvage. Les perturbations observées chez le mutant et la souche complémentée sont dues à l'effet polaire puissant de l'interruption de cipC sur l'expression des gènes en aval. L'intégration du plasmide dans le chromosome par recombinaison homologue a seule permis de restaurer le phénotype sauvage en rétablissant la succession des gènes dans le cluster. L'étude du mutant suggère un lien transcriptionnel entre les gènes du cluster.
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Dalle, Prisca. "Système intégré pour l'encapsulation monocouche de cellules." Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENS036/document.
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L'implantation d'îlots de Langerhans microencapsulés est une thérapie prometteuse pour le diabète de type 1. Le concept est de rétablir la fonction de sécrétion d'insuline tout en évitant le rejet de greffe. Les premiers essais cliniques ont reporté des résultats encourageants mais encore peu reproductibles. En effet, les techniques actuelles de production de microcapsules sont manuelles et au sein d'un même lot les capsules ne sont pas homogènes. L'utilisation de la microfluidique offre la possibilité de remédier à ce problème. Ce projet présente les différentes étapes d'optimisation d'un système microfluidique complexe qui automatise le procédé d'encapsulation monocouche de cellules dans des capsules polymériques d'alginate. Ce système comporte trois fonctions principales en série : la formation de gouttes monodisperses d'alginate en flux d'huile par un module MFFD (Micro Flow Focusing Device), le transfert de ces gouttes de la phase huileuse vers une phase aqueuse gélifiante de calcium et enfin un second transfert vers un flux à concentration physiologique. Des capsules monodisperses et sphériques ont été obtenues en sortie de ce système et des premiers tests d'encapsulation de cellules ont été réalisés. Les capsules produites par le système automatisé ont conduit à une première implantation chez le rongeur. Ce système est une première étape clé vers un dispositif instrumenté qui permettrait aux cliniciens d'encapsuler des îlots rapidement et de façon reproductible directement après leur isolement, puis de les implanter chez les patients diabétiques. Mots clés : encapsulation, îlots de Langerhans, alginate, gélification, microfluidique, automatisation, MFFD, transfert de phaseEpileptic seizures arise from pathological synchronization of neuronal ensemble.Seizures originating from primary motor cortex are often pharmacoresistant, and many times unsuitable for respective surgery because of location of epileptic focus in eloquent area. Basal ganglia play important role in seizure propagation. Micro electrode recordings performed during previous studies indicated that input structures of basal ganglia such as GPe, Putamen and Subthalamic nucleus (STN) are strongly modified during seizures. For example the mean firing rate of neurons of the STN and Putamen increased and the percentage of oscillatory neurons synchronized with the ictal EEG was higher during seizures as compared to interictal periods. Pilot studies in humans have shown the possible beneficial effect of chronic DBS applied to STN in treatment of pharmacoresistant motor seizures. Our study was aimed at studying the therapeutic effect of electrical stimulation of input structures of basal ganglia . We first developed a stable, predictable primate model of focal motor epilepsy by intracortical injection of penicillin and we documented it's pharmacoresistence. We then stereotactically implanted DBS electrodes in the STN and Putamen. The stimulator was embedded at the back of the animals. Subthreshold electrical stimulations at 130 Hz were applied to STN. Stimulator was turned ON when penicillin was injected. Sham stimulation at 0 volt was used as a control situation, each monkey being its own control. The time course, number and duration of seizures occurring in each epochs of 1 h were compared during ON and sham stimulation periods. Each experimental session lasted uptoo 6 hours,We also studied preventive high frequency stimulation of STN and subthershold low frequency stimulation of Putamen with 5 Hz and 20 Hz in the same model .Finally we studied combined effects of high frequency STN and low frequency Putamen stimulation in one monkey Results: Data was analysed from 1572 seizures in 30 experiments in three monkeys for chronic STN stimulation , 454 seizures in 10 experiments in one moneky during preventive STN stimulation ,289 seizures from 14 experiments in two monkeys during LFS putamen stimulation and 477 seizures from 10 sessions during combined STN and Putamen stimulation in one monkey The best results were observed during chronic STN stimulation The occurrence of first seizure was significantly delayed as compared to sham situation. Total time spent in focal seizures was significantly reduced by ≥69% on an average (p ≤0.05) after STN stimulation, due to a significant decrease in the number of seizures especially so during the first 3 hours after stimulation. The duration of individual seizures reduced moderately. Bipolar and monopolar stimulation modes were equally effective Preventive HFS STN (in one specimen) was not found to be superior to acute stimulation. LFS Putamen alone was effective but mainly in first two hours of stimulation .In a combined HFS STN and LFS Putamen stimulation the effect of stimulation in terms of seizure control was modest and poor compared to HFS STN alone or LFS Putamen alone. This study provides original data in primates showing the potential therapeutic effect of chronic HFS-STN DBS to treat focal motor seizures . A discussion explaining these
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De, Smedt Thibaut. "Maturation et apoptose des cellules dendritiques in vivo." Doctoral thesis, Universite Libre de Bruxelles, 1998. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212028.
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Pezzella, Francesca Maria. "Studio ex vivo di rigenerazione epatica:valutazione biologico funzionale." Thesis, Università degli Studi di Catania, 2011. http://hdl.handle.net/10761/233.
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Le cellule staminali mesenchimali possono essere considerarate una valida alternativa terapeutica al trapianto d'organo nel trattamento delle patologie epatiche. Il nostro studio, su modello animale, si propone di valutare parametri di funzionalita epatica (GOT,GPT,FAL) a diversi timepoints dopo la rigenerazione endogena con MSCs previa necrosi CCL4 indotta, rispetto al gruppo controllo di rigenerazione endogena spontanea. Tutti i ratti recuperano la funzionalita' epatica ma differente e il tempo di recupero che e risultato significativamente piu breve nel gruppo trattato con MSCs. Questi dati dimostrano che il trattamento con le cellule staminali mesenchimali potrebbe essere una efficace e valida terapia per le epatopatie.Mesenchymal stem cells can represent a therapeutic alternative to organ transplantation in the treatment of liver diseases.This animal model study investigated liver function parameters (GOT, GPT, ALP) at different timepoints after organ regeneration with MSCs after CCL4-induced necrosis compared with normal organ regeneration controls.Hepatic functional recovery was significantively smaller in rats treated with stem cells compared with controls.These data demonstrated that the use of MSCs may ameliorate the treatment of hepatic desease
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Nicolini, Benedetta <1981>. "Effetto della combinazione di cellule CD4+CD25+, cellule staminali emopoietiche CD34+e ATG nella prevenzione della risposta alloreattiva delle cellule T in vitro ed in vivo." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3557/1/nicolini_benedetta_tesi_dottorato.pdf.
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Il trapianto delle cellule staminali emopoietiche umane CD34+ in combinazione con le cellule T regolatorie CD4+/CD25+ FoxP3+ (Tregs) potrebbe prevenire l'alloreattività verso le cellule staminali emopoietiche e ridurre il rischio di rigetto in trapianti allogenici HLA non correlati.
Per dimostrare questa ipotesi abbiamo messo in coltura le cellule CD34+ e le cellule CD4+/CD25+ isolate con metodica immunomagnetica (Miltnyi Biotec)da sangue periferico non manipolato,sangue periferico mobilizzato con G-CSF o da Cordone ombelicale.
Gli esperimenti svolti in vitro, hanno evidenziato che le cellule Tregs arricchite, ottenute dalla stessa fonte delle cellule CD34+( autologhe), mostravano un effetto inibitorio maggiore sulle celulle T alloreattive, rispetto alle cellule Tregs ottenute da un donatore terzo(allogenico).Inoltre l'attività immunosoppressoria delle Tregs era mantenuta dopo stimolazione con cellule CD34+ allogeniche e i Tregs non modificavano l'attività clonogenica delle cellule staminali CD34+. Avendo ottenuto questi dati in vitro abbiamo trapiantato in topi NOD/SCID le cellule Tregs e le cellule CD34+ in rapporto 1:1 o 1:2 ed è stato osservato un normale attecchimento delle cellule staminali.
Incubando queste cellule con dosi fisiologiche di timoglobulina derivata da coniglio (nota molecola immunosopressoria) non veniva modificato il numero dei Tregs dopo 6 giorni di coltura. Dopo l'esposizione alla Timoglobulina, inoltre, i Tregs mantenevano la loro attività soppressoria, aumentava l'espressione del recettore chemochinico CCR7, e venivano rilasciate diverse citochine principalmente l'interleuchina 10(IL-10). Tali dati dimostrano come sia le cellule tregs autologhe che quelle allogeniche potrebbero essere trapiantate insieme alle cellule staminali CD34+ dopo un regime preparatorio di terapia che include la timoglobulina. A tale scopo sono state eseguite selezioni di Tregs da aferesi di donatori sani mobilizzati con G-CSF su scala clinica utilizzando biglie immunomagnetiche Clinical grade (Miltenyi Biotec) e sono state confrontate 2 modalità di selezione con due o tre passaggi con o senza la deplezione dei monociti CD14+.Si è dimostrato così che è possibile selezionare un numero uguale di CD34+ e Tregs ,che con la metodica che prevede la deplezione dei monociti si ottiene una popolazione di cellule Tregs più pura ( > 80%) e infine le applicazioni possibili di questi risultati includo: trapianto di cellule CD34+ del donatore insieme a cellule Tregs in trapianti aploidentici ; infusione of cellule tregs isolate da PBSC mobilizzati con G-nei casi di pazienti con GVHD steroide-resistente; infusione di G-Tregs del donatore nei casi di rigetto di organo trapiantato da of donatore ancora vivente.
Books on the topic "Cellule vive"
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Hoffman, Robert M., ed. In Vivo Cellular Imaging Using Fluorescent Proteins. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-61779-797-2.
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In vivo migration of immune cells. Boca Raton, Fla: CRC Press, 1987.
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In vivo cellular imaging using fluorescent proteins: Methods and protocols. New York: Humana Press, 2012.
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1951-, Imhof Beat A., Berrih-Aknin Sonia 1955-, Ezine Sophie 1954-, and International Conference on Lymphatic Tissues and Germinal Centers in Immune Reactions (10th : 1990 : Compiègne, France), eds. Lymphatic tissues and in vivo immune responses. New York: M. Dekker, 1991.
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Ferrick, David A. Transgenic mice as a in vivo model for self reactivity. Austin: R.G. Landes Co., 1994.
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Morowitz, Harold J. Beginnings of cellular life: Metabolism recapitulatesbiogenesis. New Haven: Yale University Press, 1992.
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Celle qui monte du désert: Récit d'une conversion. Paris: Médiaspaul, 2015.
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Biology of normal proliferating cells in vitro: Relevance for in vivo aging. Basel: Karger, 1988.
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Beginnings of cellular life: Metabolism recapitulates biogenesis. New Haven: Yale University Press, 1992.
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Vision: Quand la quête d'aujourd'hui était celle d'hier. Rouyn-Noranda, Québec: ABC de l'édition, 2010.
Find full textBook chapters on the topic "Cellule vive"
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London, Robert E. "In Vivo 2H NMR Studies of Cellular Metabolism." In In Vivo Spectroscopy, 277–306. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4757-9477-9_6.
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Frischknecht, Freddy, Rogerio Amino, Blandine Franke-Fayard, Chris Janse, Andrew Waters, and Robert Ménard. "Imaging Parasites in Vivo." In Imaging Cellular and Molecular Biological Functions, 345–64. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71331-9_12.
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Flaherty, Lynne, John M. Harlan, and Robert K. Winn. "Blockade of Leukocyte Adhesion in in Vivo Models of Inflammation." In Cellular Adhesion, 153–66. Boston, MA: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4615-2466-3_9.
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Miller, Sandra K., and Gabriel A. Elgavish. "Shift-Reagent-Aided 23Na NMR Spectroscopy in Cellular, Tissue, and Whole-Organ Systems." In In Vivo Spectroscopy, 159–240. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4757-9477-9_4.
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Van der Gouw, Lex. "Tracking and Traceability." In Quality Management and Accreditation in Hematopoietic Stem Cell Transplantation and Cellular Therapy, 83–88. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-64492-5_10.
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AbstractThe ability to trace a cellular product from donor to patient and vice versa is essential for the patient’s safety. Uniform product description as well as standardization of product labelling is necessary to ensure adequate tracking and tracing of cellular products.Also, with the increasing use of automated systems, accurate and unambiguous electronic transfer of product information is critical.Standardization comprises several elements which together will form an ‘information environment’. Together with electronic standards such as ISBT128 and Eurocode, this will further enhance safety, accuracy and efficiency in tracking and tracing cellular products.
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Chan, Justin, Jayant P. Menon, Rohit Mahajan, and Rahul Jandial. "In Vivo Imaging of Cellular Transplants." In Frontiers in Brain Repair, 1–12. New York, NY: Springer New York, 2010. http://dx.doi.org/10.1007/978-1-4419-5819-8_1.
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Andes, David R. "In Vivo Candida Device Biofilm Models." In Candida albicans: Cellular and Molecular Biology, 93–113. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-50409-4_7.
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Henschler, R., J. Winkler, D. Möbest, A. Spyridonidis, W. Lange, and R. Mertelsmann. "Recent Developments in the Ex Vivo Manipulation of Hematopoietic Cells from Bone Marrow and Blood." In Cellular Therapy, 37–53. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-662-03509-2_3.
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Friedman, Mark T., Kamille A. West, Peyman Bizargity, Kyle Annen, H. Deniz Gur, and Timothy Hilbert. "Serendipity, C’est La Vie." In Immunohematology, Transfusion Medicine, Hemostasis, and Cellular Therapy, 437–41. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-14638-1_59.
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Braun, Christina, Robert Knüppel, Jorge Perez-Fernandez, and Sébastien Ferreira-Cerca. "Non-radioactive In Vivo Labeling of RNA with 4-Thiouracil." In Ribosome Biogenesis, 199–213. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2501-9_12.
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AbstractRNA molecules and their expression dynamics play essential roles in the establishment of complex cellular phenotypes and/or in the rapid cellular adaption to environmental changes. Accordingly, analyzing RNA expression remains an important step to understand the molecular basis controlling the formation of cellular phenotypes, cellular homeostasis or disease progression. Steady-state RNA levels in the cells are controlled by the sum of highly dynamic molecular processes contributing to RNA expression and can be classified in transcription, maturation and degradation. The main goal of analyzing RNA dynamics is to disentangle the individual contribution of these molecular processes to the life cycle of a given RNA under different physiological conditions. In the recent years, the use of nonradioactive nucleotide/nucleoside analogs and improved chemistry, in combination with time-dependent and high-throughput analysis, have greatly expanded our understanding of RNA metabolism across various cell types, organisms, and growth conditions.In this chapter, we describe a step-by-step protocol allowing pulse labeling of RNA with the nonradioactive nucleotide analog, 4-thiouracil, in the eukaryotic model organism Saccharomyces cerevisiae and the model archaeon Haloferax volcanii.
Conference papers on the topic "Cellule vive"
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Zwick, H., B. E. Stuck, W. R. Elliott, D. J. Lund, S. T. Schuschereba, and G. Li. "An Animal Model for In-Vivo Characterization of Laser Induced Retinal cellular Pathology and Recovery Processes." In In Vivo optical Imaging at the NIH. Washington, D.C.: Optica Publishing Group, 1999. http://dx.doi.org/10.1364/ivoi.1999.msi31.
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In the high numerical aperture eye of the snake, the photoreceptor matrix can be imaged in vivo under anesthetized conditions, providing a unique capability to image acute photic damage effects on photoreceptor and anterior retinal blood cell dynamics in response to retinal laser injury. New insights into photic damage and neural repair mechanisms become available from such in vivo cellular observations.
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Boppart, Stephen A., Wolfgang Drexler, Uwe Morgner, Franz X. Kärtner, and James G. Fujimoto. "Ultrahigh Resolution and Spectroscopic OCT Imaging of Cellular Morphology and Function." In In Vivo optical Imaging at the NIH. Washington, D.C.: Optica Publishing Group, 1999. http://dx.doi.org/10.1364/ivoi.1999.msi56.
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Optical coherence tomography (OCT) is a promising optical microscopy technique which enables ultrahigh-resolution, spectroscopic, in vivo imaging in transparent and non-transparent biological specimens. This is achieved by exploiting the short temporal coherence of ultrabroad bandwidth light sources to image morphological features at subcellular resolution at depths beyond that of conventional bright-field and confocal microscopes. Extraction of spatially resolved spectroscopic information is feasible to improve image contrast and to obtain functional or biochemical properties of the investigated tissue. The potential for using OCT to image the morphological expression of genes involved in normal and abnormal development has been shown in common developmental biology animal models. In vivo imaging of single cell morphology, mitosis, and migration, as well as preliminary spectroscopic imaging, is demonstrated.
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Goldschmidt, Ezequiel, Meghan Schneck, David Gau, Aidan Dadey, Bruno L., Zhipeng Li, Sally Wenzel, Eric Wang, Carl Snyderman, and Paul Garnder. "Regenerated Oxidized Cellulose (Surgicel) Induces Nasal Epithelial Necrosis In Vivo by Acidifying the Cellular Environment." In 29th Annual Meeting North American Skull Base Society. Georg Thieme Verlag KG, 2019. http://dx.doi.org/10.1055/s-0039-1679506.
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Oraevsky, Alexander, Elena V. Savateeva, Alexander A. Karabutov, Brent Bell, Richard Johnigan, Jay P. Pasricha, and Massoud Motamedi. "Application of the confocal opto-acoustic tomography in detection of squamous epithelial carcinoma at early stages." In In Vivo optical Imaging at the NIH. Washington, D.C.: Optica Publishing Group, 1999. http://dx.doi.org/10.1364/ivoi.1999.dis153.
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Confocal opto-acoustic transducer (COAT) was developed and applied for detection of early stages of squamous cell carcinoma in hamster model of oral cancer. COAT is a novel imaging modality capable of detecting profiles of wide-band ultrasonic transients at the site of pulsed laser irradiation. Animal model of oral cancer used Syrian golden hamsters treated with carcinogenic agent, DMBA (9,10-Dimethyl-1,2-Benzanthracene). Opto-acoustic tomography was applied to visualize the course of cancer development from normal to displasia, to carcinoma in situ, to invasive carcinoma. Correlation of the opto-acoustic images with H&E histology sections confirmed that early cancer lesions, invisible by gross observation, could be detected with the opto-acoustic tomography. Our hypothesis is that pronounced contrast revealed by the opto-acoustic tomography between normal and malignant tissues is associated with increased sizes and concentration of cellular nuclei at the stage of microscopic displasia and with tumor angiogenesis at the later stages. Characteristic feature of carcinoma progression as demonstrated by COAT is the gradual loss of layered structure in mucous and developing heterogeneity.
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Win, Zaw, Geoffrey D. Vrla, Emily N. Sevcik, and Patrick W. Alford. "Microfluidic Device for Spatial Control of Cell Seeding in Engineered Tissues." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14510.
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In vivo tissues have finely controlled hierarchical structure that is often difficult to mimic in vitro. Microfabrication techniques, such as microcontact printing, can be used to reproduce tissue structure in vitro by controlling cell shape and orientation [1]. Several recent results suggest that cellular organization and structure can influence tissue function in engineered tissues [2–4]. For example, using microcontact printing and muscular thin film technology, we recently demonstrated that engineered vascular tissues whose smooth muscle cells possessed more elongated spindle-like geometries, similar to in vivo structure, exhibited more physiological contractile function [5]. In these studies, cells were seeded using traditional imprecise seeding methods. But recent results have shown that cell-cell coupling plays a significant role in functional contractility [6], suggesting that not only cellular geometry, but cell-cell organization, within a tissue is important to reproduce in engineered tissues to mimic in vivo function.
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Zawadzki, Robert J., Suman Pilli, Dae Yu Kim, Sandra Balderas-Mata, Arlie G. Capps, and John S. Werner. "Three-dimensional cellular resolution in-vivo retinal imaging." In Bio-Optics: Design and Application. Washington, D.C.: OSA, 2011. http://dx.doi.org/10.1364/boda.2011.bma3.
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Porter, Jason. "In vivo cellular imaging of the rodent retina." In Frontiers in Optics. Washington, D.C.: OSA, 2009. http://dx.doi.org/10.1364/fio.2009.fthq3.
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Leforestier, Claire. "Fontaines narratives de Jean GIono." In XXV Coloquio AFUE. Palabras e imaginarios del agua. Valencia: Universitat Politècnica València, 2016. http://dx.doi.org/10.4995/xxvcoloquioafue.2016.3039.
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La qualité matricielle de l'eau pour la psyché est un lieu commun qui ne présente d'intérêt que si la généralité cède devant l'examen de réalisations singulières. Avec une simple scène d'enfants, Jean Giono révèle, dans « Jeux ou la naumachie », que le lit d'eau vive fait celui de la fiction. Du contact avec l'eau naissent en même temps la créature et le créateur. Fontaine, ruisseau, fleuve, mer... les diverses eaux de son œuvre sont corrélées à des êtres ou à des métamorphoses, leur présence amorce un cours d'événements, l'élément donne lieu à l'écoulement ou à la dérive : la narration même. Il importe de rechercher les traits distinctifs de ces eaux, non par souci d'inventaire, mais pour dégager certaines propriétés fondamentales. Si la plus significative est bien celle de la poïèse, propriété génétique, la plus éclatante est la qualité magique de l'eau de mer... La dimension tellurique de l'œuvre a été largement explorée. L'eau a beau y être moins « décrite » que l'air et la lumière, autres éléments vitaux majeurs dont le conteur s'emploie à restituer le fascinant pouvoir d'animation, ses aspects (multiples) et ses fonctions (cruciales) méritent que l'on s'y penche. Pour connaître les prestiges des eaux, il faut d'abord rencontrer les initiés: Pétrus, le fontainier de « L'Eau vive », Antonio, l'homme-fleuve du Chant du monde, l'aiguadier de Noé... autant de « caractères » de la vie aquatique dont l'écrivain marque la valeur et les pouvoirs. Il faut en outre s'intéresser aux correspondances favorites du poète-romancier : l'eau, relativement peu comparée (en huile, en métal ou en écailles) sert en revanche fréquemment de comparant, vivifiant nombre d'éléments naturels, tant il est vrai que, chez Giono, la crue de la fiction tend à faire acquérir à toute représentation la dimension du grand large.DOI: http://dx.doi.org/10.4995/XXVColloqueAFUE.2016.3039
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Boppart, Stephen A., Gary J. Tearney, Brett E. Bouma, James G. Fujimoto, and Mark E. Brezinski. "Optical Coherence Tomography of Embryonic Morphology During Cellular Differentiation." In Advances in Optical Imaging and Photon Migration. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/aoipm.1996.cit231.
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Improved imaging of morphological changes has the potential of offering new insight into the complex process of embryonic development. Optical coherence tomography (OCT), is a new imaging technique for performing in vivo cross-sectional imaging of architectural morphology by measuring backscattered infrared light. This study investigates the application of OCT for imaging developing structure in Xenopus laevis (African frog) and Brachydanio rerio (zebra fish), two developmental biology animal models. Images are compared to corresponding histological preparations. Cross sectional imaging can be performed and structural morphology identified at greater imaging depths than possible with confocal and light microscopy. Repeated OCT imaging may be performed in vivo in order to track structural changes throughout development. Imaging in vivo microscopic embryonic morphology with OCT is a fundamental biological research application for the study of genetic disease.
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Ng, Colin, and Amrinder Nain. "Cellular Dynamics on Aligned Fibrous PLGA Scaffolds." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-54014.
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Understanding cellular dynamics is fundamental to increasing the healing and regenerative capacity of biomedical scaffolds. The ability to investigate environmental cues and cell-cell interactions in vitro with successful translation to in vivo therapies will enhance many tissue engineering technologies. Understanding the dynamics of a cell in response to external mechanical stimuli can help achieve directed cellular migration by varying cellular environment geometries. Customized scaffolds can then be designed to achieve desired cellular migration rates, cell-cell interaction pathways, increased proliferation and directed cellular differentiation platforms to achieve tissue engineering specific goals. In this study, a unique fiber manufacturing platform known as STEP (Spinneret-based Tunable Engineered Parameters) is used to create and manipulate geometrical cues for cellular migration. The cell’s reaction to these geometric cues provides valuable insight into cellular behavior, which can be used to determine the optimal engineered microenvironment. We envision that studying cellular behavior on STEP enabled customized scaffolds will aid in the design and fabrication of accurate mechanistic environments for different cell types which can then be coupled with chemical cues to achieve desired results.
Reports on the topic "Cellule vive"
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Eldar, Avigdor, and Donald L. Evans. Streptococcus iniae Infections in Trout and Tilapia: Host-Pathogen Interactions, the Immune Response Toward the Pathogen and Vaccine Formulation. United States Department of Agriculture, December 2000. http://dx.doi.org/10.32747/2000.7575286.bard.
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In Israel and in the U.S., Streptococcus iniae is responsible for considerable losses in various fish species. Poor understanding of its virulence factors and limited know-how-to of vaccine formulation and administration are the main reasons for the limited efficacy of vaccines. Our strategy was that in order to Improve control measures, both aspects should be equally addressed. Our proposal included the following objectives: (i) construction of host-pathogen interaction models; (ii) characterization of virulence factors and immunodominant antigens, with assessment of their relative importance in terms of protection and (iii) genetic identification of virulence factors and genes, with evaluation of the protective effect of recombinant proteins. We have shown that two different serotypes are involved. Their capsular polysaccharides (CPS) were characterized, and proved to play an important role in immune evasion and in other consequences of the infection. This is an innovative finding in fish bacteriology and resembles what, in other fields, has become apparent in the recent years: S. iniae alters surface antigens. By so doing, the pathogen escapes immune destruction. Immunological assays (agar-gel immunodiffusion and antibody titers) confirmed that only limited cross recognition between the two types occurs and that capsular polysaccharides are immunodominant. Vaccination with purified CPS (as an acellular vaccine) results in protection. In vitro and ex-vivo models have allowed us to unravel additional insights of the host-pathogen interactions. S. iniae 173 (type II) produced DNA fragmentation of TMB-8 cells characteristic of cellular necrosis; the same isolate also prevented the development of apoptosis in NCC. This was determined by finding reduced expression of phosphotidylserine (PS) on the outer membrane leaflet of NCC. NCC treated with this isolate had very high levels of cellular necrosis compared to all other isolates. This cellular pathology was confirmed by observing reduced DNA laddering in these same treated cells. Transmission EM also showed characteristic necrotic cellular changes in treated cells. To determine if the (in vitro) PCD/apoptosis protective effects of #173 correlated with any in vivo activity, tilapia were injected IV with #173 and #164 (an Israeli type I strain). Following injection, purified NCC were tested (in vitro) for cytotoxicity against HL-60 target cells. Four significant observations were made : (i) fish injected with #173 had 100-400% increased cytotoxicity compared to #164 (ii) in vivo activation occurred within 5 minutes of injection; (iii) activation occurred only within the peripheral blood compartment; and (iv) the isolate that protected NCC from apoptosis in vitro caused in vivo activation of cytotoxicity. The levels of in vivo cytotoxicity responses are associated with certain pathogens (pathogen associated molecular patterns/PAMP) and with the tissue of origin of NCC. NCC from different tissue (i.e. PBL, anterior kidney, spleen) exist in different states of differentiation. Random amplified polymorphic DNA (RAPD) analysis revealed the "adaptation" of the bacterium to the vaccinated environment, suggesting a "Darwinian-like" evolution of any bacterium. Due to the selective pressure which has occurred in the vaccinated environment, type II strains, able to evade the protective response elicited by the vaccine, have evolved from type I strains. The increased virulence through the appropriation of a novel antigenic composition conforms with pathogenic mechanisms described for other streptococci. Vaccine efficacy was improved: water-in-oil formulations were found effective in inducing protection that lasted for a period of (at least) 6 months. Protection was evaluated by functional tests - the protective effect, and immunological parameters - elicitation of T- and B-cells proliferation. Vaccinated fish were found to be resistant to the disease for (at least) six months; protection was accompanied by activation of the cellular and the humoral branches.
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Mendez, Juan, and Bruce Stillman. Investigation of the Causes of Breast Cancer at the Cellular Level: Isolation of In Vivo Binding Sites of the Human Origin Recognition Complex. Fort Belvoir, VA: Defense Technical Information Center, August 2001. http://dx.doi.org/10.21236/ada398164.
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Mendez, Juan, and Bruce Stillman. Investigation of the Causes of Breast Cancer at the Cellular Level: Isolation of In Vivo Binding Sites of the Human Origin Recognition Complex. Fort Belvoir, VA: Defense Technical Information Center, August 2002. http://dx.doi.org/10.21236/ada409474.
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Mendez, Juan, and Bruce Stillman. Investigation of the Causes of Breast Cancer at the Cellular Level: Isolation of In Vivo Binding Sites of the Human Origin Recognition Complex. Fort Belvoir, VA: Defense Technical Information Center, August 2000. http://dx.doi.org/10.21236/ada390687.
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Davidson, Irit, Hsing-Jien Kung, and Richard L. Witter. Molecular Interactions between Herpes and Retroviruses in Dually Infected Chickens and Turkeys. United States Department of Agriculture, January 2002. http://dx.doi.org/10.32747/2002.7575275.bard.
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Tumors in commercial poultry are caused mainly by infection with avian herpes and retroviruses, the herpesvirus Marek's disease virus (MDV) and the retroviruses, reticuloendotheliosis (REV), lymphoid leukosis, subgroups A-I and J (ALV and ALV-J) in chickens, or Iymphoprolipherative disease (LPDV) in turkeys. Infection with one virus aggravates the clinical outcome of birds that are already infected by another oncogenic virus. As these viruses do not interfere for infection, MDV and one or more retroviruses can infect the same flock, the same bird and the same cell. While infecting the same cell, herpes and retroviruses might interact in at least three ways: a) Integration of retrovirus genomes, or genomic fragments (mainly the LTR) into MDV;b) alteration of LTR-driven expression of retroviral genes by MDV immediate- early genes, and c) by herpesvirus induced cellular transcriptional factors. The first type of molecular interaction have been demonstrated to happen efficiently in vitro by Dr. Kung, in cases multiple infection of cell cultures with MDV and REV or MDV and ALV. Moreover, Dr. Witter showed that an in vitro-created recombinant, RM1, had altered in vitro replication and in vivo biological properties. A more comprehensive characterization of RM1 was carried out in the present project. We sought to highlight whether events of such integrations occur also in the bird, in vivo. For that, we had first to determine the prevalence of dually-infected individual birds in commercial flocks, as no systematic survey has been yet reported. Surprisingly, about 25% of the commercial flocks infected with avian oncogenic viruses had a multiple virus infection and 5% of the total samples ana lysed had multiple virus sequences. Then, we aimed to evaluate and characterize biologically and molecularly the resulting recombinants, if formed, and to analyse the factors that affect these events (virus strains, type and age of birds and time interval between the infection with both viruses). The perception of retrovirus insertions into herpesviruses in vivo is not banal, as the in vivo and in vitro systems differ in the viral-target cells, lymphocytes or fibroblasts, in the MDV-replicative type, transforming or productive, and the immune system presence. We realized that previous methods employed to study in vitro created recombinant viruses were not adequate for the study of samples taken directly from the bird. Therefore, the Hot Spot-combined PCR was developed based on the molecularly known RM1 virus. Also, the PFGE that was used for tissue cultured-MDV separation was inefficient for separating MDV from organs, but useful with feather tips as a source of bird original MDV. Much attention was dedicated now to feathers, because if a recombinant virus would be formed in vivo, its biological significance would be evident by horizontal dissemination through the feathers. Major findings were: a) not only in vitro, but also in vivo MDV and retrovirus co-infections lead to LTR integrations into MDV. That was shown by the detection of chimeric molecules. These appeared in low quantities and as quasispecies, thus interfering with sequence analysis of cloned gel-purified chimeric molecules. Mainly inserts were located in the repeat long MDV fragments. In field birds chimeric molecules were detected at a lower frequency (2.5%) than in experimentally infected birds (30-50%). These could be transmitted experimentally to another birds by inoculation with chimeric molecules containing blood. Several types of chimeric molecules were formed, and same types were detected in birds infected by a second round. To reproduce viral integrations, in vivo infection trials were done with field inoculate that contained both viruses, but the chimeric molecule yield was undetectable.
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Fromm, A., Avihai Danon, and Jian-Kang Zhu. Genes Controlling Calcium-Enhanced Tolerance to Salinity in Plants. United States Department of Agriculture, March 2003. http://dx.doi.org/10.32747/2003.7585201.bard.
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The specific objectives of the proposed research were to identify, clone and characterize downstream cellular target(s) of SOS3 in Arabidopsis thaliana, to analyze the Ca2+-binding characteristics of SOS3 and the sos3-1 mutant and their interactions with SOS3 cellular targets to analyze the SOS3 cell-specific expression patterns, and its subcellular localization, and to assess the in vivo role of SOS3 target protein(s) in plant tolerance to salinity stress. In the course of the study, in view of recent opportunities in identifying Ca2+ - responsive genes using microarrays, the group at Weizmann has moved into identifying Ca2+-responsive stress genes by using a combination of aqeuorin-based measurements of cytosolic Ca and analysis by DNA microarrays of early Ca-responsive genes at the whole genome level. Analysis of SOS3 (University of Arizona) revealed its expression in both roots and shoots. However, the expression of this gene is not induced by stress. This is reminiscent of other stress proteins that are regulated by post-transcriptional mechanisms such as the activation by second messengers like Ca. Further analysis of the expression of the gene using promoter - GUS fusions revealed expression in lateral root primordial. Studies at the Weizmann Institute identified a large number of genes whose expression is up-regulated by a specific cytosolic Ca burst evoked by CaM antagonists. Fewer genes were found to be down-regulated by the Ca burst. Among the up-regulated genes many are associated with early stress responses. Moreover, this study revealed a large number of newly identified Ca-responsive genes. These genes could be useful to investigate yet unknown Ca-responsive gene networks involved in plant response to stress.
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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.
Full textAbstract:
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.
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Sukenik, Assaf, Paul Roessler, and John Ohlrogge. Biochemical and Physiological Regulation of Lipid Synthesis in Unicellular Algae with Special Emphasis on W-3 Very Long Chain Lipids. United States Department of Agriculture, January 1995. http://dx.doi.org/10.32747/1995.7604932.bard.
Full textAbstract:
Various unicellular algae produce omega-3 (w3) very-long-chain polyunsaturated fatty acids (VLC-PUFA), which are rarely found in higher plants. In this research and other studies from our laboratories, it has been demonstrated that the marine unicellular alga Nannochloropsis (Eustigmatophyceae) can be used as a reliable and high quality source for the w3 VLC-PUFA eicosapentaenoic acid (EPA). This alga is widely used in mariculture systems as the primary component of the artificial food chain in fish larvae production, mainly due to its high EPA content. Furthermore, w3 fatty acids are essential for humans as dietary supplements and may have therapeutic benefits. The goal of this research proposal was to understand the physiological and biochemical mechanisms which regulate the synthesis and accumulation of glycerolipids enriched with w3 VLC-PUFA in Nannochloropsis. The results of our studies demonstrate various aspects of lipid synthesis and its regulation in the alga: 1. Variations in lipid class composition imposed by various environmental conditions were determined with special emphasis on the relative abundance of the molecular species of triacylglycerol (TAG) and monogalactosyl diacylglycerol (MGDG). 2. The relationships between the cellular content of major glycerolipids (TAG and MGDG) and the enzymes involved in their synthesis were studied. The results suggested the importance of UDP-galactose diacylglycerol galactosyl (UDGT) in regulation of the cellular level of MGDG. In a current effort we have purified UDGT several hundredfold from Nannochloropsis. It is our aim to purify this enzyme to near homogeneity and to produce antibodies against this enzyme in order to provide the tools for elucidation of the biochemical mechanisms that regulate this enzyme and carbon allocation into galactolipids. 3. Our in vitro and in vivo labeling studies indicated the possibility that phosphatidylcholine (PC) and phosphatidylethanolamine (PE) are associated with desaturation of the structural lipids, whereas shorter chain saturated fatty acids are more likely to be incorporated into TAG. 4. Isolation of several putative mutants of Nannochloropsis which appear to have different lipid and fatty acid compositions than the wild type; a mutant of a special importance that is devoid of EPA was fully characterized. In addition, we could demonstrate the feasibility of Nannochloropsis biomass production for aquaculture and human health: 1) We demonstrated in semi-industrial scale the feasibility of mass production of Nannochloropsis biomass in collaboration with the algae plant NBT in Eilat; 2) Nutritional studies verified the importance algal w3 fatty acids for the development of rats and demonstrated that Nannochloropsis biomass fed to pregnant and lactating rats can benefit their offspring.
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Barash, Itamar, and Robert Rhoads. Translational Mechanisms Governing Milk Protein Levels and Composition. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7696526.bard.
Full textAbstract:
Original objectives: The long-term goal of the research is to achieve higher protein content in the milk of ruminants by modulating the translational apparatus of the mammary gland genetically, nutritionally, or pharmacologically. The short-term objectives are to obtain a better understanding of 1) the role of amino acids (AA) as regulators of translation in bovine and mouse mammary epithelial cells and 2) the mechanism responsible for the synergistic enhancement of milk-protein mRNA polyadenylation by insulin and prolactin. Background of the topic: In many cell types and tissues, individual AA affect a signaling pathway which parallels the insulin pathway to modulate rates and levels of protein synthesis. Diverse nutritional and hormonal conditions are funneled to mTOR, a multidomain serine/threonine kinase that regulates a number of components in the initiation and elongation stages of translation. The mechanism by which AA signal mTOR is largely unknown. During the current grant period, we have studied the effect of essential AA on mechanisms involved in protein synthesis in differentiated mammary epithelial cells cultured under lactogenic conditions. We also studied lactogenic hormone regulation of milk protein synthesis in differentiated mammary epithelial cells. In the first BARD grant (2000-03), we discovered a novel mechanism for mRNA-specific hormone-regulated translation, namely, that the combination of insulin plus prolactin causes cytoplasmic polyadenylation of milk protein mRNAs, which leads to their efficient translation. In the current BARD grant, we have pursued the signaling pathways of this novel hormone action. Major conclusions/solutions/achievements: The positive and negative signaling from AA to the mTOR pathway, combined with modulation of insulin sensitization, mediates the synthesis rates of total and specific milk proteins in mammary epithelial cells. The current in vitro study revealed cryptic negative effects of Lys, His, and Thr on cellular mechanisms regulating translation initiation and protein synthesis in mammary epithelial cells that could not be detected by conventional in vivo analyses. We also showed that a signaling pathway involving Jak2 and Stat5, previously shown to lead from the prolactin receptor to transcription of milk protein genes, is also used for cytoplasmic polyadenylation of milk protein mRNAs, thereby stabilizing these mRNAs and activating them for translation. Implications: In vivo, plasma AA levels are affected by nutritional and hormonal effects as well as by conditions of exercise and stress. The amplitude in plasma AA levels resembles that applied in the current in vitro study. Thus, by changing plasma AA levels in the epithelial cell microenvironment or by sensitizing the mTOR pathway to their presence, it should be possible to modulate the rate of milk protein synthesis. Furthermore, knowledge that phosphorylation of Stat5 is required for enhanced milk protein synthesis in response to lactogenic opens the possibility for pharmacologic approaches to increase the phosphorylation of Stat5 and, thereby, milk protein production.
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Hansen, Peter J., Zvi Roth, and Jeremy J. Block. Improving oocyte competence in dairy cows exposed to heat stress. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7598163.bard.
Full textAbstract:
Original Objectives. The overall goal is to develop methods to increase pregnancy rate in lactating dairy cows exposed to heat stress through methods that minimize damage to the oocyte and embryo caused by heat stress. Objectives were as follows: (1) examine the protective effects of melatonin on developmental competence of oocytes exposed to elevated temperature in vitro; (2) test whether melatonin feeding can improve developmental competence of oocytes in vivo and, if so, whether effects are limited to the summer or also occur in the absence of heat stress; and (3) evaluate the effectiveness of improving fertility by facilitating follicular turnover in the summer and winter. Revised Objectives. (1) Examine protective effects of melatonin and follicular fluid on developmental competence of oocytes exposed to elevated temperature in vitro; (2) examine the protective effects of melatonin on developmental competence of embryos exposed to elevated temperature in vitro; (3) evaluate effectiveness of improving fertility by administering human chorionicgonadotropin (hCG) to increase circulating concentrations of progesterone and evaluate whether response to hCG depends upon genotype for four mutations reported to be related to cow fertility; and (4) identify genes with allelic variants that increase resistance of embryos to heat shock. Background. The overall hypothesis is that pregnancy success is reduced by heat stress because of damage to the oocyte and cleavage-stage embryo mediated by reactive oxygen species (ROS), and that fertility can be improved by provision of antioxidants or by removing follicles containing oocytes damaged by heat stress. During the study, additional evidence from the literature indicated the potential importance of treatment with chorionicgonadotropin to increase fertility of heat- stressed cows and results from other studies in our laboratories implicated genotype as an important determinant of cow fertility. Thus, the project was expanded to evaluate hCG treatment and to identify whether fertility response to hCG depended upon single nucleotide polymorphisms (SNP) in genes implicated as important for cow fertility. We also evaluated whether a SNP in a gene important for cellular resistance to heat stress (HSPA1L, a member of the heat shock protein 70 family) is important for embryonic resistance to elevated temperature. Major conclusions, solutions & achievements. Results confirmed that elevated temperature increases ROS production by the oocyte and embryo and that melatonin decreases ROS. Melatonin reduced, but did not completely block, damaging effects of heat shock on the oocyte and had no effect on development of the embryo. Melatonin was protective to the oocyte at 0.1-1 μM, a concentration too high to be achieved in cows. It was concluded that melatonin is unlikely to be a useful molecule for increasing fertility of heat-stressed cows. Treatment with hCG at day 5 after breeding increased first-service pregnancy rate for primiparous cows but not for multiparous cows. Thus, hCG could be useful for increasing fertility in first-parity cows. The effectiveness of hCG depended upon genotype for a SNP in COQ9, a gene encoding for a mitochondrial-function protein. This result points the way to future efforts to use genetic information to identify populations of cows for which hormone treatments will be effective or ineffective. The SNP in HSPA1L was related to embryonic survival after heat shock. Perhaps, genetic selection for mutations that increase cellular resistance to heat shock could be employed to reduce effects of heat stress on fertility. Implications, both scientific and agricultural. This project has resulted in abandonment of one possible approach to improve fertility of the heat-stressed cow (melatonin therapy) while also leading to a method for improving fertility of primiparous cows exposed to heat stress (hCG treatment) that can be implemented on farms today. Genetic studies have pointed the way to using genetic information to 1) tailor hormonal treatments to cow populations likely to respond favorably and 2) select animals whose embryos have superior resistance to elevated body temperatures.