Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

In the last decade, there has been renewed interest in the use of granulocyte transfusions to treat infections in individuals with compromised immune systems. However, granulocytes only remain functional for about a day after isolation and this short shelf life is a significant drawback. Cryopreservation would allow long term storage of granulocytes, but an effective cryopreservation method is currently unavailable. The following study was performed to provide membrane permeability values for multiple cryoprotectants in hopes of aiding the optimization of cryoprotectant addition and removal and minimizing the detrimental effects of the process. The granulocytes were separated from whole blood using centrifugation with Polymorphprep as the separating agent. The cellular membrane permeability values were then measured using a Beckman Coulter Counter Multisizer 3 under custom setup conditions. The cryoprotectants studied were glycerol, DMSO, ethylene glycol, and propylene glycol at the respective total concentrations of 1, 2, 2, 1 Osm/kg at temperatures of 4, 21, and 37 °C. The resulting membrane solute permeability values at 20 °C reference temperature for DMSO, ethylene glycol, glycerol, and propylene glycol were respectively 5.96, 7.84, 0.950, and 3.45 um/min and the Arrhenius activation energies were respectively 60.4, 58.7, 68.2, and 62.3 kJ/mol. The resulting hydraulic permeability values in the same order and temperature were 0.196, 0.189, 0.259, and 0.113 um/(atm min) and the Arrhenius activation energies were respectively 56.3, 60.7, 68.5, and 47.1 kJ/mol. It is anticipated that these permeability values will aid in the development of successful cryopreservation procedures for granulocytes. / Graduation date: 2013

Thèse--Méd.--Paris 7, C.H.U. Bichat-Beaujon, 1974. N°: 54. / Bibliogr. p. 101-106.

Au cours de cette étude, une corrélation statistiquement significative entre le niveau d'anxiété et le statut oxydatif périphérique a été mise en évidence. En effet, plus le niveau d'anxiété augmente plus le niveau intracellulaire des espèces réactives de l'oxygène (ERO) des granulocytes est élevé. Les résultats enregistrés ont montré que les granulocytes du sang des souris anxieuses sont sujets à des dommages oxydatifs qui entraînent leurs dysfonctionnements. Ces résultats mettent en évidence l'impact du stress anxiogène sur le statut oxydatif et sur l'accumulation des ERO intracellulaires qui est un facteur étiologique essentiel. En outre, nous avons trouvé que l'acide chlorogénique contenu dans des variétés de prunes dont la mirabelle permet la protection des granulocytes contre le stress oxydant et possède des propriétés anxiolytiques. Le potentiel antiradicalaire de sept variétés de prunes françaises dont la mirabelle a été comparativement évalué par le test ABTS. L'effet protecteur de ces prunes sur les granulocytes du sang contre le stress oxydant a été évalué en comparaison au pouvoir protecteur de la vitamine C. La présente étude a montré que les polyphénols sont les supports majeurs de l'activité antioxydante des prunes et souligne l'intérêt préventif de la consommation des prunes dans l'apparition de plusieurs troubles liés au stress oxydant. Le profil chimique des principaux polyphénols des prunes a été déterminé par CLHP et révèle que l'acide néochlorogénique est le polyphénol majoritaire. Notre méthode de travail à partir des prunes a permis d'étendre ce protocole à la quantification des phénols totaux, des flavonoïdes totaux et de l'activité antioxydante totale de plusieurs autres agroressources. Ainsi, l'effet protecteur du fruit du Momordica charantia L. et des feuilles du Desmodium adscendens L. contre le stress oxydant des granulocytes a été révélé, ce qui augmente la valeur thérapeutique de ces plantes / In this study, the linear and significant correlation between level of anxiety and peripheral oxidative status has been established. Indeed, the more the level of anxiety increases the more the intracellular level of reactive oxygen species of granulocytes is elevated. Our findings showed that the blood granulocytes of anxious mice may be more prone to oxidative damages altering their functions. These results highlighted the impact of anxiogen stress on the cellular oxidative status, and on the accumulation of intracellular ROS which is an essential etiologic factor. We have also found that chlorogenic acid protected granulocytes from oxidative stress, and possess anxiolytic properties. The antiradical power of seven varieties of French plums including the Mirabelle was comparatively evaluated in this study using ABTS test. Moreover, the protective effect of these plums on freshly isolated granulocytes from oxidative stress was also investigated in comparison with the vitamin C. Our results showed that polyphenols were the major contributor in the antioxidant activity exhibited by plums, and emphasize the preventive advantage of plum consummation from diseases linked to oxidative stress. The chemical profile permitted to reveal that neochlorogenic acid was the predominant polyphenolic in tested plums. The previsiouly protocol has been extended to some plants to quantify total phenolics, total flavonoids and total antioxidant activity. The protective effect of Momordica charantia L. fruit and of Desmodium adscendens L. leaves on granulocytes from oxidative stress has been highlighted, which gives to these plants an additional therapeutic value

No description available.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2007. / Härtill 4 uppsatser.

Thèse ou mémoire avec insertion d'articles. / La transfusion de concentrés de granulocytes (CG) représente une option thérapeutique pour les patients neutropéniques confrontés à des infections potentiellement mortelles résistantes aux agents antimicrobiens. Cette approche vise à augmenter temporairement le nombre de neutrophiles circulants afin de combattre les agents pathogènes. L'une des principales limites de la transfusion de CG réside dans la brève durée de vie des neutrophiles et la diminution rapide de leur efficacité clinique (< 24 h). Cette contrainte accroît la charge logistique des centres de collecte, complique le transport et restreint l'accès à une thérapie cellulaire efficace. Des études ont rapporté que la concentration cellulaire élevée contenue dans les CG entraîne une diminution significative de la viabilité et de la fonction antimicrobienne des cellules après 24 heures. Bien que la dilution 1 pour 8 et l'ajout de solutions additives aux CG aient permis de prolonger ces facteurs jusqu'à 48 heures, ces méthodes n'étaient pas entièrement adaptées à l'utilisation clinique en raison du volume excessif des transfusions. La présente étude a permis de développé une solution additive adaptée à la clinique, permettant de maintenir la viabilité des neutrophiles pendant 48 heures. Cette solution, composée principalement d'une solution additive pour globules rouges (AS-3) ainsi qu'une pour plaquettes (Plasma-Lyte) supplémentée de tampons et d'albumine (Alburex), a réussi à étendre l'activité antimicrobienne des neutrophiles, dont la phagocytose et la production intracellulaire d'espèces réactives de l'oxygène (ROS), jusqu'à 72 heures. Même la fonction la plus touchée par l'entreposage, à savoir la migration, a été maintenue pendant au moins 24 heures. Cependant, après 24 heures, on observe une augmentation significative de la production de ROS extracellulaires en présence de cette solution, ce qui pourrait avoir des conséquences négatives pour le receveur. Si, lors de l'entreposage, l'on tient compte des autres types cellulaires, comme les globules rouges et les plaquettes, et du délai de traitement du sang de 16 à 24 heures nécessaires pour la préparation de CG à partir du pool de leucocytes résiduels, cette solution ne semble pas suffisante pour prolonger la conservation des neutrophiles. Une éventuelle amélioration des conditions d'entreposage des CG pourrait garantir l'efficacité thérapeutique des produits sanguins destinés à la transfusion, malgré les délais de production et de transport qui peuvent parfois excéder 24 heures. / Transfusion of granulocyte concentrates (GCs) represents a therapeutic alternative for neutropenic patients with life-threatening infections resistant to antimicrobial treatments. This approach offers temporary antimicrobial protection by increasing the circulating neutrophil count. The main limitations of GC transfusion is the short shelf-life of neutrophils and the rapid decline in their clinical efficacy (< 24 h). This constraint increases the logistical burden on collection centers, complicates transport and restricts access to effective cell therapy. Previous studies have reported that the high cell concentration contained in CGs leads to a significant decrease in cell viability and antimicrobial function after 24 h. While dilution 1-in-8 and supplementation of GCs with additive solutions was successful in prolonging these factors for up to 48 h, these methods were not entirely suitable for clinical use due to excessive transfusion volume. The present study developed an additive solution specifically adapted for clinical use, allowing neutrophil viability to be maintained for up to 48 hours. The present study developed an additive solution specifically adapted for clinical use, allowing neutrophil viability to be maintained for up to 48 hours. This solution, composed mainly of a red blood cell additive solution (AS-3) and platelet additive solution (Plasma-Lyte) supplemented with buffers and albumin (Alburex), successfully extended the antimicrobial activity of neutrophils, including phagocytosis and intracellular production of reactive oxygen species (ROS), for up to 72 hours. Even the most affected function, e.g. migration, was maintained for at least 24 hours. However, after 24 hours, there was a significant increase in extracellular ROS production in the presence of this solution, which could have negative consequences for the recipient. If other cell types, such as red blood cells and platelets, are considered during storage, along with the 16 to 24-hour blood processing time required to prepare GCs from the residual leukocyte pool, this solution does not appear to be sufficient to prolong neutrophil preservation. Improving GC storage conditions could guarantee the therapeutic efficacy of blood products intended for transfusion, despite production and transport times that can sometimes exceed 24 hours.

Apoptosis is a physiological form of cell death. It is a highly evolutionarily conserved process that is non-inflammatory or anti-inflammatory in nature. This anti-inflammatory nature of apoptosis is evident by the fact that neutrophils are histologically absent from sites where homeostatic apoptosis rates are high. The rapid phagocytosis of apoptotic cells as a means to prevent the release of noxious inflammatory compounds also accounts for the anti-inflammatory environment of such sites. However, the mechanisms that enable mononuclear phagocytes to migrate to sites where homeostatic apoptosis rates are high, and not granulocytes, the professional phagocytes that accumulate at sites of inflammation, have not been determined yet. Using Burkitt’s lymphoma (BL) as a model of apoptosis, the aim of this thesis was to identify the regulatory mechanisms or factors underlying the non-phlogistic features of sites where homeostatic apoptosis rates are high and in particular, those preventing the recruitment of neutrophils - a major granulocyte subclass to these sites. BL is a highly aggressive B cell lymphoma that is mainly characterised by a high rate of apoptosis. By carrying out a series of in vitro chemotaxis assays and biochemical approaches, it was found in this thesis that BL cells actively inhibit neutrophil migration by releasing factors that were identified to be lactoferrin, a 80 kDa iron-binding glycoprotein with anti-bacterial and anti-inflammatory properties. It was further demonstrated that lactoferrin selectively inhibited migration of granulocytes (both neutrophils and eosinophils) but not mononuclear phagocytes and this effect was irrespective of its iron saturation status and the chemoattractant used. Also, lactoferrin potently inhibited neutrophil migration, as assessed by thioglycollate-induced in vivo model of mouse peritonitis. This anti-inflammatory function of lactoferrin was attributed to its effect on granulocyte signalling pathways that regulate cell adhesion and motility. Finally, it was demonstrated that in cell types of diverse lineages, induction of apoptosis results in de novo synthesis and secretion of lactoferrin. In subsequent proliferation assays determining the in vitro growth of a number of BL cell types, it was demonstrated that lactoferrin is an essential component of BL cells and promotes their proliferation, as its antibody-mediated neutralisation or shRNA-mediated expression knockdown, reduced BL cell growth. Together, the results of this thesis identified lactoferrin as one of the few characterised antiinflammatory components of the apoptosis milieu that negatively regulate granulocyte migration. This effect may provide opportunities for broad therapeutic interventions concerning the use of lactoferrin in chronic inflammatory conditions characterised by aberrant neutrophil influx as well as atopic allergic disorders, such as asthma. Moreover, based on the tumour-supporting role of lactoferrin described in this study, targeting its expression in tumours could lead to tumour regression and thus, be a promising therapeutic molecule in tumour immunotherapy.

No description available.

Thèse de doctorat : Sciences de la vie et de la santé : Paris 12 : 2003. / Titre provenant de l'écran-titre.