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Role of CD36 in Platelet FunctionArunima, Ghosh January 2007 (has links)
No description available.
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Differentiation of regulatory myeloid cells and the potential for therapeutic applicationsVanGundy, Zachary Curtis 17 October 2014 (has links)
No description available.
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Restoration of Lung Sphingosine Levels Improves the Immune Response to Infection in a Murine Two-hit Sepsis/Pneumonia ModelWhitacre, Brynne E. January 2017 (has links)
No description available.
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CONTROLLED PRESENTATION OF GENETIC MATERIAL WITHIN STEM CELL CONDENSATIONS FOR REGULATION OF CELL BEHAVIOR FOR BONE TISSUE ENGINEERINGMcMillan, Alexandra 01 June 2018 (has links)
No description available.
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Test de génotypage plaquettaire in vitro à base de sandwichs de microparticules biofonctionnalisées : détection par capteur de fluorescence à ondes évanescentes, imagerie de fluorescence et cytométrie en fluxCornillon, Amandine January 2014 (has links)
Résumé : Cette thèse porte sur l’élaboration d’un outil de capture d’ADN permettant d’identifier une mutation génétique (SNP) grâce à la formation de sandwichs avec des particules de carboxylatex biofonctionnalisées avec des oligonucléotides couplée à une détection de la fluorescence. Le modèle biologique choisi pour ce projet est le génotypage plaquettaire et plus particulièrement la recherche du gène biallélique HPA-1.
Le principal objectif de ce travail a été d’optimiser un outil de capture préalablement développé dans l’équipe (Trévisan, 2011) afin de réduire le nombre d’étapes et de simplifier la mise en œuvre globale du test en modifiant les interactions moléculaires utilisée pour capturer l’ADN cible et en utilisant des particules fluorescentes comme élément de détection. En présence d’ADN cible, des sandwichs sont formés entre les particules fluorescentes et les particules magnétiques biofonctionnalisées. Ces sandwichs sont purifiés par séparation magnétique et la fluorescence est détectée par trois méthodes : la cytométrie en flux, l’imagerie de fluorescence et l’Evareader (détection par ondes évanescentes).
Dans un premier temps, les paramètres de fonctionnalisation chimique et biologique des différentes particules (magnétiques et fluorescentes) ont été déterminés et optimisés ainsi que les conditions d’hybridation pour la capture de l’ADN cible.
Ensuite, la formation des sandwichs et leur détection ont été suivies par des mesures de fluorescence en utilisant trois méthodes différentes : la cytométrie en flux, l’imagerie de fluorescence et l’Evareader (capteur à ondes évanescentes). Les résultats obtenus avec les différentes méthodes de détection sont concordants et montrent que l’outil de capture d’ADN développé permet de capturer la cible synthétique (oligonucléotide) HPA-1 en réduisant le temps d’analyse de 45 min. Dans nos conditions, le test permet de discriminer l’allèle a de l’allèle b du gène HPA-1 qui ne diffère que d’un nucléotide. Le rapport des signaux de fluorescence issus du sandwich spécifique et du sandwich non spécifique est d’environ 2,5 à 3. Ce rapport devra être amélioré par la suite, en optimisant les conditions de formation des sandwichs.
La prochaine étape consistera à optimiser le système de capture d’ADN développé pour gagner en spécificité et déterminer la limite de détection du test. Ce test devra également être validé avec des échantillons biologiques.
A plus long terme, la fluorescence pourra être détectée par un photodétecteur miniaturisé actuellement développé à l’Université de Sherbrooke. Des études préliminaires présentées dans ce manuscrit montrent les potentialités de ce nouveau transducteur. // Abstract : This thesis is about the development of a new assay to capture DNA. This assay is based on the formation of sandwiches between biofunctionnalized with oligonucleotides carboxylatex microparticles combined with fluorescence detection. It should be able to discriminate single nucleotide polymorphism (SNP). This assay is designed to be applied to platelet genotyping for the research of the gene HPA-1.
The main goal of this work was to improve an assay previously developed (Trévisan, 2011) by INL and EFS Rhône-Alpes. The objectives are to reduce the number of
steps and to simplify the test. To do so, the molecular interactions used in order to capture
target DNA are modified and fluorescent microparticles are used for the detection. In the
presence of target DNA, sandwiches are formed between both biofunctionnalized
fluorescent and magnetic particles. Those sandwiches are purified through magnetic
separation. Then, fluorescence is detected by three methods: flow cytometry, fluorescence imaging and Evareader (detection with an evanescent wave).
First, chemical and biological parameters for the functionalization of the different
particles (magnetic and fluorescent) are determined. The conditions for the capture of target DNA were optimized. Then, the formation and the detection of the sandwiches were estimated by measuring the fluorescence using three different methods: flow cytometry, fluorescence imaging and Evareader. The results obtained with the three methods are consistent. They show that the new system enables to capture synthetic target (oligonucleotide) HPA-1 with a reduction of total time analysis of 45 min. In our conditions, SNP can be discriminated for HPA-1 gene. For this discrimination, the fluorescence signal ratio about 2.5 to 3. This ratio should be improved by optimizing the conditions of sandwiches formation. Next step will consist in the optimization of the system developed to capture DNA in order to gain specificity and to determine the limit of detection. This test should also be validated with biological samples.
In the long term, fluorescence could be detected by a miniaturized photodetector
developed in the University of Sherbrook. Preliminary studies presented in this manuscript show the potentialities of this new transducer.
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Chitosan derived formulations and EmzaloidTM technology for mucosal vaccination against diphtheria : nasal efficacy in mice / Erika M. TruterTruter, Erika Mare January 2005 (has links)
Previous studies have demonstrated that chitosan and its derivative, N-trimethyl chitosan
chloride (TMC) are effective and safe absorption enhancers to improve mucosal delivery
of macromolecular drugs including vaccines. Furthermore, chitosan and TMC can easily
form microparticles and nanoparticles, which have the ability to encapsulate large
amounts of antigens. Emzaloid™ technology has proven in the past to be an effective
delivery system for numerous drugs. Emzaloids can entrap, transport and deliver large
amounts of drugs including vaccines.
In this study, the ability of chitosan microparticles and nanoparticles, TMC microparticles
as well as micrometer and nanometer range Emzaloids to enhance both the systemic and
mucosal (local) immune response against diphtheria toxoid (DT) after nasal
administration in mice was investigated.
The above mentioned formulations were prepared and characterised according to size and
morphology. DT was then associated to the chitosan microparticles and nanoparticles as
well as TMC microparticles to determine the antigen loading and release. It was found
that the loading efficacy of the formulations was 88.9 %, 27.74 % and 63.1 %
respectively, and the loading capacity of the formulations was 25.7 %, 8.03 % and
18.3 %.
DT loaded and unloaded (empty) chitosan microparticles and nanoparticles, TMC
microparticles, micrometer and nanometer range Emzaloids as well as DT in phosphate
buffered saline (PBS) were administered nasally to mice. Mice were also vaccinated
subcutaneous with DT associated to alum as a positive control. All mice were vaccinated
on three consecutive days in week 1 and boosted in week 3. Sera was analysed for anti-
DT IgG and nasal lavages were analysed for anti-DT IgA using an enzyme linked
imrnunosorbent assay (ELISA).
In the study conducted to determine the systemic (IgG) and local (IgA) immune
responses it was seen that DT associated to all the experimental formulations produced a
systemic immune response. The said formulations produced a significantly higher
systemic immune response when compared to the formulation of DT in PBS.
Furthermore, the mice vaccinated with DT associated to the TMC formulations showed a
much higher systemic immune response than the mice that were vaccinated
subcutaneously with DT associated to alum, whereas the other formulations produced
systemic immune responses that were comparable to that of DT associated to alum. It was
also found that DT associated to the experimental formulations produced a local immune
response, however only DT associated to TMC microparticles produced a consistent local
immune response.
It can be concluded from the in vivo experiments that the TMC formulations, moreover,
the TMC microparticles is the most effective and promising formulation for the nasal
delivery of vaccines. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2005.
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Chitosan derived formulations and EmzaloidTM technology for mucosal vaccination against diphtheria : nasal efficacy in mice / Erika M. TruterTruter, Erika Mare January 2005 (has links)
Previous studies have demonstrated that chitosan and its derivative, N-trimethyl chitosan
chloride (TMC) are effective and safe absorption enhancers to improve mucosal delivery
of macromolecular drugs including vaccines. Furthermore, chitosan and TMC can easily
form microparticles and nanoparticles, which have the ability to encapsulate large
amounts of antigens. Emzaloid™ technology has proven in the past to be an effective
delivery system for numerous drugs. Emzaloids can entrap, transport and deliver large
amounts of drugs including vaccines.
In this study, the ability of chitosan microparticles and nanoparticles, TMC microparticles
as well as micrometer and nanometer range Emzaloids to enhance both the systemic and
mucosal (local) immune response against diphtheria toxoid (DT) after nasal
administration in mice was investigated.
The above mentioned formulations were prepared and characterised according to size and
morphology. DT was then associated to the chitosan microparticles and nanoparticles as
well as TMC microparticles to determine the antigen loading and release. It was found
that the loading efficacy of the formulations was 88.9 %, 27.74 % and 63.1 %
respectively, and the loading capacity of the formulations was 25.7 %, 8.03 % and
18.3 %.
DT loaded and unloaded (empty) chitosan microparticles and nanoparticles, TMC
microparticles, micrometer and nanometer range Emzaloids as well as DT in phosphate
buffered saline (PBS) were administered nasally to mice. Mice were also vaccinated
subcutaneous with DT associated to alum as a positive control. All mice were vaccinated
on three consecutive days in week 1 and boosted in week 3. Sera was analysed for anti-
DT IgG and nasal lavages were analysed for anti-DT IgA using an enzyme linked
imrnunosorbent assay (ELISA).
In the study conducted to determine the systemic (IgG) and local (IgA) immune
responses it was seen that DT associated to all the experimental formulations produced a
systemic immune response. The said formulations produced a significantly higher
systemic immune response when compared to the formulation of DT in PBS.
Furthermore, the mice vaccinated with DT associated to the TMC formulations showed a
much higher systemic immune response than the mice that were vaccinated
subcutaneously with DT associated to alum, whereas the other formulations produced
systemic immune responses that were comparable to that of DT associated to alum. It was
also found that DT associated to the experimental formulations produced a local immune
response, however only DT associated to TMC microparticles produced a consistent local
immune response.
It can be concluded from the in vivo experiments that the TMC formulations, moreover,
the TMC microparticles is the most effective and promising formulation for the nasal
delivery of vaccines. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2005.
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Test de génotypage plaquettaire in vitro à base de sandwich de microparticules biofonctionnalisées : Détection par capteur de fluorescence à ondes évanescentes, imagerie de fluorescence et cytométrie en flux / Biofunctionnalized microparticles based sandwiches for in vitro platelet genotyping test : detection by evanescent waves biosensor, fluorescence scanner and flow cytometryCornillon, Amandine 18 December 2014 (has links)
Cette thèse porte sur l’élaboration d’un outil de capture d’ADN permettant d’identifier une mutation génétique (SNP) grâce à la formation de sandwichs avec des particules de carboxylatex biofonctionnalisées avec des oligonucléotides couplée à une détection de la fluorescence. Le modèle biologique choisi pour ce projet est le génotypage plaquettaire et plus particulièrement la recherche du gène biallélique HPA-1. Le principal objectif de ce travail a été d’optimiser un outil de capture préalablement développé dans l’équipe (Trévisan, 2011) afin de réduire le nombre d’étapes et de simplifier la mise en oeuvre globale du test en modifiant les interactions moléculaires utilisée pour capturer l’ADN cible et en utilisant des particules fluorescentes comme élément de détection. En présence d’ADN cible, des sandwichs sont formés entre les particules fluorescentes et les particules magnétiques biofonctionnalisées. Ces sandwichs sont purifiés par séparation magnétique et la fluorescence est détectée par trois méthodes : la cytométrie en flux, l’imagerie de fluorescence et l’Evareader (détection par ondes évanescentes). Dans un premier temps, les paramètres de fonctionnalisation chimique et biologique des différentes particules (magnétiques et fluorescentes) ont été déterminés et optimisés ainsi que les conditions d’hybridation pour la capture de l’ADN cible. Ensuite, la formation des sandwichs et leur détection ont été suivies par des mesures de fluorescence en utilisant trois méthodes différentes : la cytométrie en flux, l’imagerie de fluorescence et l’Evareader (capteur à ondes évanescentes). Les résultats obtenus avec les différentes méthodes de détection sont concordants et montrent que l’outil de capture d’ADN développé permet de capturer la cible synthétique (oligonucléotide) HPA-1 en réduisant le temps d’analyse de 45 min. Dans nos conditions, le test permet de discriminer l’allèle a de l’allèle b du gène HPA-1 qui ne diffère que d’un nucléotide. Le rapport des signaux de fluorescence issus du sandwich spécifique et du sandwich non spécifique est d’environ 2,5 à 3. Ce rapport devra être amélioré par la suite, en optimisant les conditions de formation des sandwichs. La prochaine étape consistera à optimiser le système de capture d’ADN développé pour gagner en spécificité et déterminer la limite de détection du test. Ce test devra également être validé avec des échantillons biologiques. A plus long terme, la fluorescence pourra être détectée par un photodétecteur miniaturisé actuellement développé à l’Université de Sherbrooke. Des études préliminaires présentées dans ce manuscrit montrent les potentialités de ce nouveau transducteur. / This thesis is about the development of a new assay to capture DNA. This assay is based on the formation of sandwiches between biofunctionnalized with oligonucleotides carboxylatex microparticles combined with fluorescence detection. It should be able to discriminate single nucleotide polymorphism (SNP). This assay is designed to be applied to platelet genotyping for the research of the gene HPA-1. The main goal of this work was to improve an assay previously developed (Trévisan, 2011) by INL and EFS Rhône-Alpes. The objectives are to reduce the number of steps and to simplify the test. To do so, the molecular interactions used in order to capture target DNA are modified and fluorescent microparticles are used for the detection. In the presence of target DNA, sandwiches are formed between both biofunctionnalized fluorescent and magnetic particles. Those sandwiches are purified through magnetic separation. Then, fluorescence is detected by three methods: flow cytometry, fluorescence imaging and Evareader (detection with an evanescent wave). First, chemical and biological parameters for the functionalization of the different particles (magnetic and fluorescent) are determined. The conditions for the capture of target DNA were optimized. Then, the formation and the detection of the sandwiches were estimated by measuring the fluorescence using three different methods: flow cytometry, fluorescence imaging and Evareader. The results obtained with the three methods are consistent. They show that the new system enables to capture synthetic target (oligonucleotide) HPA-1 with a reduction of total time analysis of 45 min. In our conditions, SNP can be discriminated for HPA-1 gene. For this discrimination, the fluorescence signal ratio about 2.5 to 3. This ratio should be improved by optimizing the conditions of sandwiches formation. Next step will consist in the optimization of the system developed to capture DNA in order to gain specificity and to determine the limit of detection. This test should also be validated with biological samples. In the long term, fluorescence could be detected by a miniaturized photodetector developed in the University of Sherbrook. Preliminary studies presented in this manuscript show the potentialities of this new transducer.
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Mechanisms of Anti-Angiogenic Signaling by CD36Ramakrishnan, Devi Prasadh 13 February 2015 (has links)
No description available.
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Formulation, characterisation and in vivo efficacy of dapsone and proguanil in trimethylated chitosan microparticles / Jacobus van HeerdenVan Heerden, Jacobus January 2014 (has links)
Malaria is an infectious disease caused by various forms of the Plasmodium parasite. It is
responsible for thousands of deaths yearly with 90 % of those deaths being in sub-Saharan
Africa, thus making it a disease of global importance. The global burden of malaria is
worsened by resistance to current treatment, a lack in funding and limited research outputs.
More alternative ways of treatment must be explored and may include the co-formulation of
antimalarial drug substances as well as alternative ways of drug delivery.
Antifolates are drugs which interfere with an organism’s folate metabolism by inhibiting
dihydropteroate synthase (DHPS) or dihydrofolate reductase (DHFR). Dapsone is a synthetic
sulfone which has a mechanism of action that is very similar to that of sulphonamides. The
mechanism of action is characterised by the inhibition of folic acid synthesis through the
inhibition of dihydropteroate synthase (DHPS). Another antifolate drug, proguanil, is the
prodrug of cycloguanil. Its mechanism involves the inhibition of dihydrofolate reductase
(DHFR), thus inhibiting the malaria parasite to metabolise folates and therefore stunting its
growth. Unfortunately, dapsone has a serious side-effect in people with a deficiency of the
enzyme glucose-6-phosphate dehydrogenase (G6PD) causing oxidative stress on the red
blood cells leading to the rupturing of these cells.
The main objective of this study was to formulate and characterise TMC-TPP microparticles
loaded with the effective but toxic drug combination of dapsone and proguanil and to
determine if these drug-containing microparticles had in vivo efficacy against malaria.
N-trimethyl chitosan chloride (TMC), a partially quaternised chitosan derivative, shows good
water solubility across a wide pH range thus having mucoadhesive properties and excellent
absorption enhancing effects even at neutral pH. A faster, more efficient microwave
irradiation method was developed as an alternative to the conventional synthesising method
of TMC. TMC with the same degree of quaternisation (DQ), ± 60 %, was obtained in a quarter
of the reaction time (30 min) by using the newly developed method. The TMC synthesised
with the microwave irradiation method also exhibited less degradation of the polymer
structure, thus limiting the chance for the formation of any unwanted by-products (Omethylation,
N,N-dimethylation and N-monomethylation).
The formation of complexes by ionotropic gelation between TMC and oppositely charged
macromolecules, such as tripolyphosphate (TPP), has been utilised to prepare microparticles
which are a suitable drug delivery system for the dapsone-proguanil combination. Both these
drugs were successfully entrapped. These particles were characterised and the in vivo
efficacy against the malaria parasites was determined. The microparticles with both the
drugs, separately and in combination, displayed similar or better in vivo efficacy when
compared to the drugs without the TMC microparticles.
An in vitro dissolution study was also performed by subjecting the dapsone and proguanil
TMC formulations to 0.1N HCl dissolution medium. Samples were withdrawn after
predetermined time points and the drug concentration was determined with HPLC. It was
found that the TMC microparticles resulted in a sustained release profile since only 73.00 ±
1.70 % (dapsone) and 55.00 ± 1.90 % (proguanil) was released after 150 minutes. The in vivo
bioavailability of the dapsone and proguanil TMC formulations was evaluated in mice by
collecting blood samples at predetermined time points and analysing the samples with a
sensitive and accurate LC-MS/MS method. The in vivo bioavailability of the dapsone TMC
formulation relative to the normal dapsone formulation was found to be 244 % and 123 % for
the proguanil TMC formulation relative to the normal proguanil formulation.
These TMC-TPP microparticles formulations showed better in vivo efficacy and bioavailability
when compared to the normal formulation. Together with the sustained release, these
formulations may be a promising cheaper and more effective treatment against malaria. / PhD (Pharmaceutics), North-West University, Potchefstroom Campus, 2015
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