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Luhr, Katarina. "Prion processing and propagation in neuronal and dendritic cell culture models /". Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-991-9.
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White, Nicole M. "Inherent Flaw of Cholesterol Processing in Cell Culture and In Vivo Models of Cystic Fibrosis". Case Western Reserve University School of Graduate Studies / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=case1164925733.
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Dubé, Gilles. "Post-translational processing of atrial natriuretic factor. A study using a novel cell culture system". Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7779.
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In the present work, a reproducible cell culture system using adult rat atrial cardiocytes was developed to study ANF processing. Freshly isolated atrial cardiocytes stored high molecular weight ANF (38.0 $\pm$ 4.5 pg/$\mu$g of DNA) and released almost exclusively (83.3% $\pm$ 6.7%) low molecular weight ANF, at an average rate of 12 pg/hour/$\mu$g of DNA. The cell content and the rate of release of ANF decreased over 15 days in culture to 3.9 $\pm$ 1.2 pg/$\mu$g of DNA and 0.32 pg/h/$\mu$g of DNA $\pm$ 0.08 respectively and 62.7% $\pm$ 6.3% of the released peptide was of a low molecular weight. Cultures of non-cardiocytes, superfused with exogenous proANF, did not process the peptide. There was no correlation between the changes in cell population and the reduction in processing. Therefore, atrial non-cardiocytes are not involved in ANF processing. The results presented in this work vary from other reports which found that ANF processing in cultures is absent. The discrepancies may be due to differences related to serum-free culture conditions versus serum supplemented cultures. This suggests that factors present in the serum may be responsible for maintaining ANF processing activity in culture. (Abstract shortened by UMI.)
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Tapia, Delgado Felipe Ignacio [Verfasser], i Udo [Gutachter] Reichl. "Continuous upstream processing for cell culture-derived virus production / Felipe Ignacio Tapia Delgado ; Gutachter: Udo Reichl". Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2020. http://d-nb.info/1219966479/34.
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Tapia, Delgado Felipe Ignacio Verfasser], i Udo [Gutachter] [Reichl. "Continuous upstream processing for cell culture-derived virus production / Felipe Ignacio Tapia Delgado ; Gutachter: Udo Reichl". Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2020. http://d-nb.info/1219966479/34.
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Wheater, R. F. "The development of an in vitro system for an electron microscope study of procollagen processing in cell culture". Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376285.
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Debavelaere, Dorothée. "Caractérisation de progéniteurs osseux en culture, développement d'une technique ultrasonore d'analyse dynamique". Valenciennes, 1996. https://ged.uphf.fr/nuxeo/site/esupversions/155642e1-ddd5-4273-99c5-ea8f7bf9663f.
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La moelle osseuse est une source de cellules souches ostéogéniques que l'on utilise depuis peu en injection pour réparer certains retards de consolidation osseuse. Le potentiel ostéogénique variant d'un individu à l'autre, son évaluation est entreprise par la réalisation de cultures de prélèvements médullaires. Les techniques de caractérisation de cellules ostéogéniques classiquement utilisées (biologique ou biochimique) sont essentiellement qualitatives et destructives. Ceci entraine la multiplication des échantillons et rend difficile les suivis d'évolution en raison des dispersions de comportement entre cultures distinctes. Aussi, nos travaux ont consisté à développer une nouvelle technique permettant un suivi quantitatif du développement des cellules et compatible avec la stérilité nécessaire aux cultures. La méthode envisagée consiste à mesurer la réflexion d'ultrasons haute fréquence focalisés (50mhz) sur la face interne du substrat de verre sur lequel se sont développées les cellules, afin de réaliser une cartographie acoustique de chaque culture. Ces cartographies sont effectuées par utilisation des modes transversaux crées par conversion de polarisation aux interfaces. Elles permettent, après application d'un traitement d'image spécifique, de quantifier différents paramètres de type morphologique (nombre de colonies cellulaires, taille moyenne, taux de recouvrement). Ces paramètres ont été corrélés aux caractéristiques biologiques des cultures.
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MEYER, ANSTETT COLETTE. "Analyse d'images de cellules en culture : description automatique de cellules musculaires lisses vasculaires et suivi de leur comportement". Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13063.
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Developpement d'un logiciel de traitement d'image pour la reconnaissance de cellules aortiques, l'observation et la quantification des modifications au cours du temps de la forme, de la surface et de la mobilite de myocytes aortiques de rat ont pu etre visualisees. Utilisation de la morphologie mathematique comme outil d'analyse et de description de l'image
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Dempsey, Katherine. "Monitoring individual cells within cell cultures using image processing and pattern recognition techniques". Thesis, Keele University, 2017. http://eprints.keele.ac.uk/4179/.
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Cells are the building blocks of the human body which are normally specialised by type in accordance with their function. Human cells interact with each other to form the tissues that make up the body. Consequently, it is important to study the behaviour and interactions of these cells at the microscale level, so that the causes of cellular irregularities can be identified; and, possible treatments can be devised. This project aimed to create algorithms that were capable of tracking a variety of cells types within both single cultures and mixed cultures, and from this generate data that was relevant to current clinical trials. There have been successes in tracking some cells types, most notably articular chondrocytes and spinal disk cells. In terms of data generated there has been successes in a whole variety of different types of clinical trials. The algorithms used here have been able to identify the point of mitosis. They have created a better method of determining neural growth and from this have shown that neurons co-cultured with MCSs can grow in places with neural inhibitors. Through the use of algorithms that can analyse culture in three dimensional structures it has been shown that neurons are more affected by topographical cues than chemical cues in their direction of growth. It has also been shown that vesicles are more likely to appear on smaller back disk cells. In the study of gels, it has been found that the more transparent gels are better for imaging. Finally, it has been shown that MSCs and chondrocytes behave differently when in single and co-cultures. These discoveries would not have been possible without the use of the algorithms that allowed for the study of individual cells within a larger culture.
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Beck, Mike. "Molekulare Charakterisierung des Amyloidvorläuferproteins des Meerschweinchens". Doctoral thesis, Universitätsbibliothek Leipzig, 2004. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-36500.
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Die Bildung von Amyloidablagerungen ist ein Kennzeichen der Alzheimerschen Erkrankung. Hauptbestandteil dieser senilen Plaques sind sogenannte A beta Peptide, die durch proteolytische Prozessierung aus einem Vorläufermolekül (APP) gebildet werden. Die vorliegende Arbeit beschreibt die Klonierung des Meerschweinchen - APP. Diese cDNA-Sequenz zeigt auf DNA-Ebene eine Homologie zum Human-APP von ca. 90%, auf Proteinebene beträgt die Identität ca. 97 %. Damit wird ein weiterer experimenteller Beweis für die evolutionäre Konservierung des Amyloidvorläuferproteins in Säugetieren erbracht. APP mRNA wird in Meerschweinchen-Geweben ubiquitär exprimiert. Durch alternatives Spleißen wird ein zum Human-APP im wesentlichen ähnliches Isoformenmuster gebildet: Isoformen, welche eine Proteaseinhibitordomäne enthalten, werden dominierend in peripheren Organen exprimiert, dagegen ist im Zentralnervensystem das APP 695 mit über 60 % der Gesamttranskripte die bevorzugt exprimierte Isoform. Die klonierte cDNA des Meerschweinchen-APP wurde in prokaryontischen wie auch eukaryontischen Zellsystemen exprimiert. Dabei wurde die Eignung einer Anzahl von gegen Human-APP gewonnenen Antikörpern zur Detektion des Meerschweinchen-APP und seiner Prozessierungsprodukte gezeigt. Die Expression der neuronal dominierend exprimierten Isoform APP 695 des Meerschweinchen-APP in humanen Neuroblastom-Zellen zeigte keine Unterschiede hinsichtlich der APP-Prozessierung und A beta-Bildung im direkten Vergleich zu Human-APP 695. Die proteolytische Prozessierung des Proteins wurde durch Detektion der typischen Spaltprodukte in vivo (im Liquor) als auch in einem neu etablierten in vitro-Modell primär kultivierter neuronaler Zellen untersucht. Diese Zellkulturen wurden zunächst immunhistochemisch und biochemisch charakterisiert und als "mixed brain"-Typ mit einem hohen neuronalen Anteil beschrieben. Die Prozessierung des endogenen Meerschweinchen-APP in kultivierten Zellen führt dabei zur Bildung und Akkumulation aggregationsfähiger A beta - Peptide. Zur Detektion dieser Peptide wurde ein sensitiver Nachweis durch Western-Blot etabliert. Es wird damit ein Modellsystem für in vitro-Untersuchungen vorgeschlagen, welches ein Studium der Expression und Prozessierung des Amyloidvorläuferproteins unter angenähert physiologischen Bedingungen ermöglichtA beta peptides, the major component of neuritic plaques found in the brains of patients with Alzheimers disease, are derived by proteolytic processing from a larger precursor molecule (amyloid precursor protein - APP). A combination of PCR methods was used to clone and sequence APP cDNA from guinea pig (Cavia porcellus). Guinea pig APP exhibits extensive similarities to human APP in terms of primary structure, mRNA expression of differentially spliced isoforms as shown by Northern blot and RT-PCR analysis as well as proteolytic processing to amyloidogenic A beta peptides. In contrast to rat and mouse APP, guinea pig APP - recombinantly expressed in human neuroblastoma-cells - was processed indistinguishable from human APP thus excluding intrinsic sequence-specific factors influencing processing. Further studies were performed using newly established primary cell cultures of guinea pig neurons. Refined methods have been used to detect and characterize major proteolytic processing products of APP in vitro and in vivo. In conclusion, guinea pigs provide a model to study expression and processing of APP that closely resembles the physiological situation in humans and should, therefore, be important in elucidating potential strategies to prevent amyloid formation in Alzheimers Disease
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Vlachynská, Alžběta. "Metody pro obrazovou analýzu populace fotosyntetických buněčných kultur". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221387.
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This work was carried out in collaboration with the Department of Adaptive Biotechnologies, Global Change Research Centre AS CR. It deals with the quantitative analysis of photosynthetic cell cultures. It uses images captured by a confocal fluorescent microscope to the automatic determining the number of cells in the sample. The work consists of a theoretical analysis, which briefly describes fluorescence and confocal microscopy. It also concisely introduces a microscope Leica TCS SP8 X, which I used to scan data. One capture is devoted to the theory of digital image processing. The second part deskribes the development of algorithm for processing 3D data and simplified algorithm for processing 2D data and its program implementations in a programming environment MATLAB R2013b. Grafical user interface is explained in detail. Done measurement are presented at the conclusion. It mentions compiled sample preparation protocol. The results of the program are compared with manual counting. Number of cells per 1 ml are determined by created program in samples of cell cultures Chenopodium rubrum (Cr) and Solanum lycopersicum (To).
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Bradhurst, Christopher John. "Monitoring mesenchymal stem cell cultures using image processing and pattern recognition techniques". Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/43623/1/Christopher_Bradhurst_Thesis.pdf.
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Stem cells have attracted tremendous interest in recent times due to their promise in providing innovative new treatments for a great range of currently debilitating diseases. This is due to their potential ability to regenerate and repair damaged tissue, and hence restore lost body function, in a manner beyond the body's usual healing process. Bone marrow-derived mesenchymal stem cells or bone marrow stromal cells are one type of adult stem cells that are of particular interest. Since they are derived from a living human adult donor, they do not have the ethical issues associated with the use of human embryonic stem cells. They are also able to be taken from a patient or other donors with relative ease and then grown readily in the laboratory for clinical application. Despite the attractive properties of bone marrow stromal cells, there is presently no quick and easy way to determine the quality of a sample of such cells. Presently, a sample must be grown for weeks and subject to various time-consuming assays, under the direction of an expert cell biologist, to determine whether it will be useful. Hence there is a great need for innovative new ways to assess the quality of cell cultures for research and potential clinical application. The research presented in this thesis investigates the use of computerised image processing and pattern recognition techniques to provide a quicker and simpler method for the quality assessment of bone marrow stromal cell cultures. In particular, aim of this work is to find out whether it is possible, through the use of image processing and pattern recognition techniques, to predict the growth potential of a culture of human bone marrow stromal cells at early stages, before it is readily apparent to a human observer. With the above aim in mind, a computerised system was developed to classify the quality of bone marrow stromal cell cultures based on phase contrast microscopy images. Our system was trained and tested on mixed images of both healthy and unhealthy bone marrow stromal cell samples taken from three different patients. This system, when presented with 44 previously unseen bone marrow stromal cell culture images, outperformed human experts in the ability to correctly classify healthy and unhealthy cultures. The system correctly classified the health status of an image 88% of the time compared to an average of 72% of the time for human experts. Extensive training and testing of the system on a set of 139 normal sized images and 567 smaller image tiles showed an average performance of 86% and 85% correct classifications, respectively. The contributions of this thesis include demonstrating the applicability and potential of computerised image processing and pattern recognition techniques to the task of quality assessment of bone marrow stromal cell cultures. As part of this system, an image normalisation method has been suggested and a new segmentation algorithm has been developed for locating cell regions of irregularly shaped cells in phase contrast images. Importantly, we have validated the efficacy of both the normalisation and segmentation method, by demonstrating that both methods quantitatively improve the classification performance of subsequent pattern recognition algorithms, in discriminating between cell cultures of differing health status. We have shown that the quality of a cell culture of bone marrow stromal cells may be assessed without the need to either segment individual cells or to use time-lapse imaging. Finally, we have proposed a set of features, that when extracted from the cell regions of segmented input images, can be used to train current state of the art pattern recognition systems to predict the quality of bone marrow stromal cell cultures earlier and more consistently than human experts.
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Bowes, Simone. "Processing of Alzheimer's amyloid precursor protein in cultured cells". Thesis, Sheffield Hallam University, 1999. http://shura.shu.ac.uk/19377/.
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The deposition in the brain of the 4 kDa beta-amyloid peptide (betaA4), from amyloid precursor protein (APP), is a key pathology in Alzheimer's disease (AD). The single APP gene is spliced to give 3 major isoforms. In the majority of body tissues, the most common APP isoforms are APP[751] and APP[770], which both contain a Kunitz protease inhibitor (KPI) domain, APP[695] is predominant in the brain. APP is processed through several pathways, not all of which lead to betaA4 production. Central nervous system (CNS) neurones in vivo secrete betaA4, which can be detected in the cerebrospinal fluid, though it is unknown why betaA4 is deposited in the brain in AD. NTera2 (NT2) cells derived from a human teratocarcinoma were used as a model of APP processing. Retinoic acid induces these cells to differentiate into a neuronal phenotype (NT2N cells), which has been shown to closely resemble immature human CNS neurones. Both cell types produce high levels of endogenous APP.Intracellular and secreted APP was studied in both cell types by means of western blotting and immunoprecipitation with a panel of antibodies. It was found that NT2 cells predominantly make and secrete KPI containing APP. NT2N cells make and secrete predominantly APP[695] though some KPI containing APP is also present. There is evidence that neurones in the AD brain are in a state of stress, which could increase levels of APP due to a heat shock promotor region in its gene. To investigate this, NT2 cells were subjected to a heat shock, which resulted in increased levels of heat shock protein (HSP) and APP. KPI containing APP predominated, but there was no corresponding increase in secreted APP. Both cell types were also serum deprived, which resulted in little effect on protein production in NT2 stem cells. However, the neuronal cells showed a small increase in intracellular, KPI-containing APP and in HSP. A reduction in overall APP secretion, and cessation of KPI secretion accompanied this. To further investigate the effects of shock on APP production, mRNA levels in control and serum deprived NT2 and NT2N cells were studied using in situ hybridisation. Control NT2 cells contain low levels of APP751, APP695 and HSP mRNA, with higher levels of APP[770] mRNA. After serum deprivation HSP, APP[751] and APP[770] mRNA levels all rose significantly, while APP[695] mRNA levels were unchanged. Control NT2N cells contained high levels of APP695 mRNA, lower levels of APP[751] mRNA, and very low levels of APP[770] and HSP mRNA. Serum deprivation resulted in unchanged levels of APP[695] and APP[770] mRNA, while APP[751] and HSP levels were increased. These findings indicate that cellular stress can result in increased levels of APP, specifically APP[751], in both neuronal and non-neuronal cells. Increased levels of this isoform have also been reported in AD. Hence cellular stress leads to an increase in an APP isoform implicated in AD, and could also provide an explanation for the increased levels of betaA4 in the disease.
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Hameed, Radwan [Verfasser]. "Analysis of lipid uptake and processing in cultured cells / Radwan Hameed". Bonn : Universitäts- und Landesbibliothek Bonn, 2013. http://d-nb.info/1044868244/34.
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Jaccard, N. "Development of an image processing method for automated, non-invasive and scale-independent monitoring of adherent cell cultures". Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1461036/.
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Adherent cell culture is a key experimental method for biological investigations in diverse areas such as developmental biology, drug discovery and biotechnology. Light microscopy-based methods, for example phase contrast microscopy (PCM), are routinely used for visual inspection of adherent cells cultured in transparent polymeric vessels. However, the outcome of such inspections is qualitative and highly subjective. Analytical methods that produce quantitative results can be used but often at the expense of culture integrity or viability. In this work, an imaging-based strategy to adherent cell cultures monitoring was investigated. Automated image processing and analysis of PCM images enabled quantitative measurements of key cell culture characteristics. Two types of segmentation algorithms for the detection of cellular objects on PCM images were evaluated. The first one, based on contrast filters and dynamic programming was quick (<1s per 1280×960 image) and performed well for different cell lines, over a wide range of imaging conditions. The second approach, termed ‘trainable segmentation’, was based on machine learning using a variety of image features such as local structures and symmetries. It accommodated complex segmentation tasks while maintaining low processing times (<5s per 1280×960 image). Based on the output from these segmentation algorithms, imaging-based monitoring of a large palette of cell responses was demonstrated, including proliferation, growth arrest, differentiation, and cell death. This approach is non-invasive and applicable to any transparent culture vessel, including microfabricated culture devices where a lack of suitable analytical methods often limits their applicability. This work was a significant contribution towards the establishment of robust, standardised, and affordable monitoring methods for adherent cell cultures. Finally, automated image processing was combined with computer-controlled cultures in small-scale devices. This provided a first demonstration of how adaptive culture protocols could be established; i.e. culture protocols which are based on cellular response instead of arbitrary time points.
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Buergy, Alexandra. "Modulation de la texture et de la fragmentation tissulaire de fruits lors de traitements thermiques par les modes de culture et la maturation : impact sur la texture des purées Pectin modifications in raw fruits alter texture of plant cell dispersions Apple puree’s texture is independent from fruit firmness Pectin degradation explains tissue fragmentation of fruits during thermomechanical processes for puree production". Thesis, Avignon, 2021. http://www.theses.fr/2021AVIG0282.
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L’objectif de cette thèse était de comprendre comment les caractéristiques structurales des pommes peuvent être liées aux facteurs structurels des purées après cuisson et fragmentation tissulaire. Les caractéristiques structurales du fruit ont été modulées par les cultivars, les pratiques culturales et la maturation, et les conditions du procédé (thermique : 50–95 °C et mécanique : 100–3000 tr/min) ont été modulées grâce à un cuiseur-broyeur. La structure de la purée (volume occupé par les particules, taille des particules, viscosité du sérum) et la texture (viscosité, seuil d’écoulement, G’ et G’’) ont ensuite été analysées et comparées entre les matières premières et les conditions du procédé. Les pectines ont été extraites et leur composition chimique ainsi que leur structure ont été corrélées à la structure de la purée. La taille des particules s´est montré être le déterminant majeur de la texture des purées en absence de dilution ou de concentration. Le degré d’adhésion cellulaire (défini par la structure et la composition des pectines) a eu un impact plus important sur la taille des particules que la taille des cellules individuelles (définie par les cultivars ou les pratiques culturales). D’autres facteurs structuraux, tels que la viscosité du sérum ou la quantité de pulpe, n’ont contribué à la texture des purées qu’à taille de particules constante. La fragmentation tissulaire, déterminant la taille des particules pendant le procédé, a été principalement affectée par l’intensité du cisaillement. Le stockage post-récolte des pommes et des températures élevées (95 °C) ont induit une dégradation et une solubilisation des pectines, en particulier par l'hydrolyse des chaînes latérales des rhamnogalacturonanes I. Cela a réduit l’adhésion cellulaire et la fragmentation tissulaire a ainsi été favorisée. Ces résultats ont permis d´approfondir la compréhension de la fragmentation tissulaire et des changements de texture au cours du procédé ce qui permettra de fournir des directives à l’industrie pour mieux gérer la diversité et l’hétérogénéité des fruits pendant le procédé de transformation des fruits en puréeThe objective of this thesis was to understand how structural characteristics in raw apples can be linked to structural factors in purees after cooking and tissue fragmentation. Structural characteristics of the fruit were modulated by cultivars, agricultural practices and maturation, and process conditions (thermal: 50–95 °C and mechanical: 100–3000 rpm) were modulated in a cooker-cutter during processing. Puree’s structure (volume occupied by particles, particle size, serum viscosity) and texture (viscosity, yield stress, G’ and G’’) were then analysed and compared between raw materials and process conditions. Pectins were extracted and their chemical composition and structure were correlated to puree’s structure. Particle size appeared to be the most important determinant of puree’s texture when there is no dilution or concentration of the fruit tissue. The extent of cell adhesion (defined by pectin structure and composition) determined particle size more than individual cell size (defined by varietal effects or agricultural practices). Other structural factors only contributed to puree’s texture once particle size was constant. Tissue fragmentation, determining particle size during processing, was principally affected by shear intensity. Post-harvest maturity of the raw apples and high temperatures (95 °C) induced pectin degradation, especially rhamnogalacturonan I side chain hydrolysis, and solubilisation. This led to reduced cell adhesion and tissue fragmentation was additionally favoured. The results deepened the understanding of tissue fragmentation and textural changes during processing and provided guidelines for industry to manage diversity and heterogeneity of raw fruits during processing
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Rowlands, R. J. "The effects of statin treatment on the synthesis, processing, storage and exocytosis of von Willebrand factor in cultured human endothelial cells". Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1306806/.
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The circulating, pro-thrombotic glycoprotein von Willebrand factor (VWF) is essential for haemostasis, but has also been implicated in the development of atherosclerosis. The majority of plasma VWF is secreted from endothelial cells lining the blood vessels and it is unclear what influence attenuation of the endothelial cell secretory pathway might have on the physiology or pathology of VWF. Statins are inhibitors of cholesterol biosynthesis and are widely used in the treatment of cardiovascular diseases due to their cholesterol lowering ability. However, they have also been shown this research and in the literature to have 'pleiotropic effects' caused by inhibition of the synthesis of biosynthetic intermediates (such as prenyl-lipids used for modification of small GTPases) rather than cholesterol itself. As a result this research has studied the pleiotropic actions of statins on the VWF secretory pathway in cultured human umbilical vein endothelial cells (HUVEC). As well as confirming an inhibitory effect of statins on the stimulated secretion of VWF, we found that treatment of HUVEC with statins led to a decrease in the intracellular storage of both VWF and its non-covalently associated propolypeptide (Pro-region), while the intra- and extra-cellular levels of the VWF precursor, Pro-VWF, significantly increased. All these effects were rescued by addition of the geranylgeranyl lipids used for prenylation of the Rho and Rab GTPases, but not the farnesyl lipids used for the majority of Ras family members. Using specific inhibitors of the two disitinct enzymes responsible for either Rho or Rab geranylgeranylation we have uncovered a complex picture with neither inhibitor able to reproduce all of the effects of statins of VWF. In addition to VWF, we have also discovered Rab GTPase associated effects of statins on the transferrin receptor and on the recyling of a trans Golgi network associated protein (TGN-46). In conclusion this work highlights that statins do more to vasculature than simply lowering circulating cholesterol levels and extends the complex pleiotropic effects of these drugs to influencing other cellular pathways.
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Boussemaere, Luc. "Investigating off-axis digital holographic microscopy with a source of partial spatial coherence as a real-time sensor for cell cultures". Doctoral thesis, Universite Libre de Bruxelles, 2015. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209086.
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Bio-pharmaceutical industry is a vast growing market and recent recommendations of the Food and Drug Administration have put a large emphasis on the characterization of biological processes and models. As a consequence, there is a high incentive on developing modern sensors in order to more accurately monitor and control processes. In that way, Digital Holographic Microscopy (DHM) presents unique features thanks to the refocusing and quantitative phase contrast imaging capabilities. In this thesis we investigate the usage of DHM to monitor yeast cultures that are often used in both the bio-pharmaceutical and bread industries and lay the basis of a methodological framework for the study of in-line cell cultures in the context of process control. We begin with a description of Digital Holography and the microscopy setup used in the thesis as well as a detailed explanation of the image processing required to extract the holographic data and its implementation on GPU with some speed execution figures given for three popular programming paradigms. We then describe the flow setup used and infer the limitations on the dynamic range of the technique due to both Poisson statistics and overlapping phenomena. Finally, we describe an algorithm that extracts the cells position, count and morphological information such as the size, aspect ratio, circularity and refraction index. Some experimental results are presented for yeasts before drawing a general overview of the technology and its dependencies. We further end with some conclusions concerning the technology and a brief comparison with existing competitors.Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
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Hadpe, Sandeep Tamesh. "Using experimental and theoretical appoaches for understanding biotechnology unit operations". Thesis, 2017. http://localhost:8080/xmlui/handle/12345678/7454.
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"CAD/CAM laser processing as a method for integrated fabrication of microphysiological systems". Tulane University, 2020.
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Wu, Cheng-Chi, i 吳振棋. "The effects and applications of ultrafast laser pulses on the growth of cell culture and the processing of multiwall carbon nanotubes". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/33ewt8.
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碩士國立陽明大學
生醫光電工程研究所
97
The reported study in this thesis is twofold. The research work is aimed to investigate the effect of ultrafast laser on multiwall carbon nanotubes through ablation and on cell culture through laser induced shockwave. In the ablation based material processing, nano- and femtosecond laser pulses are focused to engrave fine structures on multi-layer carbon nanotube coated surface. The effects of ablation are compared. We found that both nano- and femtosecond laser pulses produced approximately the same spatial resolution or definition. Femtosecond laser pulses, however, is able to generate highly clean-cut features without much residue. For comparison, more residue were found with nanosecond laser pulses Laser-induced shockwave and cavitation is also used to generate mechanical stress on living cultured cells. We found that the laser-induced mechanical stress strongly affected the cultured cells by severely limiting or stimulating the growth, depending on the types of the cells. The growth of P19CL6 (Embryonal carcinoma) and C2C12 (muscle) cell cultures is greatly stimulated, while the growth of PC12 (Pheochromocytoma) and HeLa (cervix) is severely inhibited. Very interesting interpretation is thus implied by the above results and forms the direction of future investigation.
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Capela, Emanuel Augusto Vieira. "Innovative and sustainable platforms for the downstream processing of antibody-based biopharmaceuticals". Doctoral thesis, 2022. http://hdl.handle.net/10773/33484.
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Antibodies, and in particular immunoglobulin G (IgG), are considered as one of the spearheads of the biopharmaceutical industry, presenting high relevance for the treatment of several diseases and being sometimes the only available therapy for some pathologies. Despite their wide potential, the extraction and purification of these biomolecules from their complex biological media with high quality and purity is still based on multi-step approaches and is of high cost. Therefore, the development of alternative and cost-effective downstream processes able to provide high amounts of therapeutic antibodies at lower cost is highly demanded. Novel ionic-liquid-based (IL-based) strategies for the downstream processing of antibodies were investigated in this PhD thesis. ILs were chosen mainly due to their designer solvents character. This feature of ILs allows to tailor the polarity, interactions and selectivity of the developed processes, allowing to overcome some technical limitations of the conventional ones. Three types of IL-based platforms for antibodies downstream processing were investigated, namely aqueous biphasic systems (ABS), three-phase partitioning (TPP) and supported ionic liquids (SILs). ABS containing ILs as adjuvants were investigated, allowing the extraction and purification of human antibodies (polyclonal and monoclonal antibodies) with good performance in a single-step. More biocompatible and sustainable ILs were also studied as phase-forming compounds of ABS, while showing the possibility of using TPP approaches based on ABS for the purification and recovery of human antibodies. Finally, new chromatographic matrices were proposed based on SILs materials, able to capture and/or purify antibodies from their complex biological media through two different mechanisms, namely through the flowthrough-like and bind-and-elute-like modes. In summary, in this PhD thesis it is shown that ILs, if properly designed, can be successfully applied in the extraction, purification and/or recovery of human antibodies, being promising alternative platforms for the downstream processing of antibody-based biopharmaceuticals.Os anticorpos, e em particular a imunoglobulina G (IgG), são considerados uma das pontas de lança da indústria biofarmacêutica, apresentando elevada relevância para o tratamento de várias doenças e sendo, por vezes, a única terapia disponível para algumas patologias. Apesar do seu amplo potencial, a extração e purificação destas biomoléculas a partir dos seus meios biológicos complexos com elevada qualidade e pureza é ainda baseada em abordagens com várias etapas e com elevado custo associado. Portanto, o desenvolvimento de processos a jusante alternativos, económicos e eficientes, capazes de fornecer elevadas quantidades de anticorpos terapêuticos a um custo reduzido é altamente necessário. Novas estratégias baseadas em líquidos iónicos (LIs) foram então investigadas nesta tese de Doutoramento para o processamento a jusante de anticorpos. Os LIs foram escolhidos principalmente devido ao seu carácter de solventes customizáveis. Esta característica dos LIs permite adequar a polaridade, interações e seletividade dos processos desenvolvidos, permitindo superar algumas limitações técnicas dos processos convencionais. Três tipos de plataformas baseadas em LIs foram investigadas para o processamento a jusante de anticorpos, nomeadamente sistemas aquosos bifásicos (SAB), partição trifásica e líquidos iónicos suportados. SAB contendo LIs como adjuvantes foram investigados, permitindo a extração e purificação de anticorpos humanos (anticorpos policlonais e monoclonais) com um bom desempenho em uma única etapa. LIs mais biocompatíveis e sustentáveis foram também estudados como compostos formadores de fases de SAB, demonstrando em simultâneo a possibilidade de utilizar abordagens de partição trifásica baseadas em SAB para a purificação e recuperação de anticorpos humanos. Finalmente, foram propostas novas matrizes cromatográficas baseadas em líquidos iónicos suportados, capazes de capturar e/ou purificar anticorpos a partir dos seus meios biológicos complexos através de dois mecanismos distintos, nomeadamente através dos modos negativo e positivo. Em suma, nesta tese de Doutoramento foi demonstrado que os LIs, se adequadamente concebidos, podem ser aplicados com sucesso na extração, purificação e/ou recuperação de anticorpos humanos, sendo plataformas alternativas promissoras para o processamento a jusante de biofármacos baseados em anticorpos.
Programa Doutoral em Engenharia Química
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Beck, Mike. "Molekulare Charakterisierung des Amyloidvorläuferproteins des Meerschweinchens". Doctoral thesis, 1998. https://ul.qucosa.de/id/qucosa%3A10869.
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Die Bildung von Amyloidablagerungen ist ein Kennzeichen der Alzheimerschen Erkrankung. Hauptbestandteil dieser senilen Plaques sind sogenannte A beta Peptide, die durch proteolytische Prozessierung aus einem Vorläufermolekül (APP) gebildet werden. Die vorliegende Arbeit beschreibt die Klonierung des Meerschweinchen - APP. Diese cDNA-Sequenz zeigt auf DNA-Ebene eine Homologie zum Human-APP von ca. 90%, auf Proteinebene beträgt die Identität ca. 97 %. Damit wird ein weiterer experimenteller Beweis für die evolutionäre Konservierung des Amyloidvorläuferproteins in Säugetieren erbracht. APP mRNA wird in Meerschweinchen-Geweben ubiquitär exprimiert. Durch alternatives Spleißen wird ein zum Human-APP im wesentlichen ähnliches Isoformenmuster gebildet: Isoformen, welche eine Proteaseinhibitordomäne enthalten, werden dominierend in peripheren Organen exprimiert, dagegen ist im Zentralnervensystem das APP 695 mit über 60 % der Gesamttranskripte die bevorzugt exprimierte Isoform. Die klonierte cDNA des Meerschweinchen-APP wurde in prokaryontischen wie auch eukaryontischen Zellsystemen exprimiert. Dabei wurde die Eignung einer Anzahl von gegen Human-APP gewonnenen Antikörpern zur Detektion des Meerschweinchen-APP und seiner Prozessierungsprodukte gezeigt. Die Expression der neuronal dominierend exprimierten Isoform APP 695 des Meerschweinchen-APP in humanen Neuroblastom-Zellen zeigte keine Unterschiede hinsichtlich der APP-Prozessierung und A beta-Bildung im direkten Vergleich zu Human-APP 695. Die proteolytische Prozessierung des Proteins wurde durch Detektion der typischen Spaltprodukte in vivo (im Liquor) als auch in einem neu etablierten in vitro-Modell primär kultivierter neuronaler Zellen untersucht. Diese Zellkulturen wurden zunächst immunhistochemisch und biochemisch charakterisiert und als "mixed brain"-Typ mit einem hohen neuronalen Anteil beschrieben. Die Prozessierung des endogenen Meerschweinchen-APP in kultivierten Zellen führt dabei zur Bildung und Akkumulation aggregationsfähiger A beta - Peptide. Zur Detektion dieser Peptide wurde ein sensitiver Nachweis durch Western-Blot etabliert. Es wird damit ein Modellsystem für in vitro-Untersuchungen vorgeschlagen, welches ein Studium der Expression und Prozessierung des Amyloidvorläuferproteins unter angenähert physiologischen Bedingungen ermöglicht.A beta peptides, the major component of neuritic plaques found in the brains of patients with Alzheimers disease, are derived by proteolytic processing from a larger precursor molecule (amyloid precursor protein - APP). A combination of PCR methods was used to clone and sequence APP cDNA from guinea pig (Cavia porcellus). Guinea pig APP exhibits extensive similarities to human APP in terms of primary structure, mRNA expression of differentially spliced isoforms as shown by Northern blot and RT-PCR analysis as well as proteolytic processing to amyloidogenic A beta peptides. In contrast to rat and mouse APP, guinea pig APP - recombinantly expressed in human neuroblastoma-cells - was processed indistinguishable from human APP thus excluding intrinsic sequence-specific factors influencing processing. Further studies were performed using newly established primary cell cultures of guinea pig neurons. Refined methods have been used to detect and characterize major proteolytic processing products of APP in vitro and in vivo. In conclusion, guinea pigs provide a model to study expression and processing of APP that closely resembles the physiological situation in humans and should, therefore, be important in elucidating potential strategies to prevent amyloid formation in Alzheimers Disease.