No description available.

No description available.

No description available.

The majority of bovine mammary gland research focuses on the main cell types - mammary epithelial cells and fibroblasts. However, the extracellular matrix (ECM) within the mammary gland is also of importance for its ability to regulate cell shape, proliferation, polarity, differentiation, gene transcription, protein synthesis, and secretion. Decorin is an ECM proteoglycan known to impact mammary cell proliferation in humans and rodents. Prior to this work, very little was known about decorin in bovine mammary biology. A series of bovine mammary cell culture experiments was conducted. The first experiment demonstrated existence of decorin pathway molecules in immortalized bovine mammary cells, but stopped short of demonstrating mature decorin proteoglycan deposition into the extracellular space. During the investigation it was noted that when cultured under basal conditions, intracellular decorin core protein (DCP) localization patterns appeared to be coordinated with specific phases of the cell cycle. Therefore, the objective of the second set of experiments was to characterize DCP localization patterns in bovine mammary epithelial cells (BME) at known phases of the cell cycle. The work was carried out in two sequential experiments. The hypothesis of the first experiment was that DCP accumulates in BME during S-phase of the cell cycle; the research rejected this hypothesis. The hypothesis of the second experiment, formulated after completion of the first experiment for this objective, was that DCP accumulates in BME during metaphase of the cell cycle. However, the experiment was unable to confirm of reject this hypothesis. Major findings were that both BME and mammary fibroblasts produce DCP and known decorin pathway molecules. BME produce intracellular DCP, but it is not accumulated during the S-phase of the cell cycle. However, it is still unknown if DCP is accumulated in BME during metaphase. Future research should focus on further characterization of decorin and its associated pathway molecules to learn if decorin induces proliferation or apoptosis of bovine mammary epithelial cells. This is important because number and activity of mammary epithelial cells ultimately determine milk yield in dairy cows. Fundamental knowledge gained in this research area may one day be applied at the animal-level and lead to gains in milk production efficiency by altering the cellular composition of mammary glands. / Ph. D.

Yes / Sonic Hedgehog (SHH) is a glycoprotein associated with development that is also expressed in the adult CNS and released after brain injury. Since the SHH receptors PTCH1 (patched homolog-1) and SMO (Smoothened) are highly expressed on astrocytes, we hypothesised that SHH regulates astrocyte function. Primary mouse cortical astrocytes derived from embryonic (E15) Swiss mouse cortices, were treated with two chemically distinct agonists of the SHH pathway, which caused astrocytes to elongate and proliferate. These changes are accompanied by decreases in the major astrocyte glutamate transporter, GLT-1 and the astrocyte intermediate filament protein GFAP. Multi-site electrophysiological recordings revealed that the SHH agonist, SAG supressed neuronal firing in astrocyte-neuron co-cultures and this was abolished by the astrocyte metabolic inhibitor ethylfluoroacetate, revealing that SHH stimulation of metabolically-active astrocytes influences neuronal firing. Using 3D co-culture, MAP2 western blotting and immunohistochemistry, we show that SHH-stimulated astrocytes protect neurons from kainate induced cell death. Altogether the results show that SHH regulation of astrocyte function represents an endogenous neuroprotective mechanism. / BBSRC

No description available.

Freqüentemente as condutas terapêuticas utilizadas no tratamento de patologias bucais são cirúrgicas, resultando em falhas de continuidade da mucosa bucal. A possibilidade de obtenção de epitélios transplantáveis, a partir do cultivo in vitro de células da mucosa bucal, abre novas perspectivas de utilização, não se restringindo somente ao seu local de origem, ou seja, a boca, mas também como material de reconstrução para outras regiões, tais como: uretra, córnea, superfície ocular e epitélio córneo-limbal. Os métodos utilizados para a obtenção dessas células ainda são controversos na literatura. Neste sentido, avaliamos e comparamos a eficiência de dois métodos, enzimático e explante, para a obtenção de queratinócitos de mucosa bucal humana. Os fragmentos utilizados para a obtenção dessas células foram obtidos durante procedimentos cirúrgicos de pacientes voluntários saudáveis. Os queratinócitos foram cultivados sobre uma camada de sustentação, feeder-layer, confeccionada com fibroblastos murinos irradiados (3T3 - Swiss albino). Neste estudo foram comparados: o tempo para a obtenção dos queratinócitos, o rendimento obtido entre os dois métodos, a duração da vida útil em cultura, a capacidade que estas células tiveram em formar um epitélio in vitro e a morfologia dos mesmos. Os resultados obtidos, na avaliação dos dois métodos, comprovaram a possibilidade de obtenção dos queratinócitos, a partir de um pequeno fragmento bucal, porém pode-se verificar que existem vantagens e restrições peculiares a cada um dos métodos estudados. / The therapeutic procedures frequently used in oral treatments for the pathological diseases are surgical, resulting in failures of the mucosal continuity.The possibility to obtain transplantable oral epithelia from an in vitro cell culture opens new utilization perspectives not only to where it comes from, but also as a reconstructive matherial for other parts of the human body, such as: urethra, epithelia corneo-limbal, cornea, ocular surface. Many researchers still use controversial methods for obtaining cells. It was therefore evaluated and compared the efficiency in both methods: enzimatic and direct explant to obtain oral keratinocytes from human oral mucosa. Fragments of intra oral epithelial tissues from healthy human subjects, undergoing dental surgeries, were donated to the research project. The keratinocytes were cultivated over a feeder-layer from a previously irradiated 3T3 Swiss albino fibroblasts. In this study it was compared the time needed in the cell obtaintion, the best cell amount between both methods, the life-span, the cell capacity to form an in vitro epithelia and its morphologic structure. The results in the accessment of both methods have shown the possibility to obtain keratinocytes from a small oral fragment, but at the same time we may verify the advantages and peculiar restrictions for each one of both analyzed methods.

Freqüentemente as condutas terapêuticas utilizadas no tratamento de patologias bucais são cirúrgicas, resultando em falhas de continuidade da mucosa bucal. A possibilidade de obtenção de epitélios transplantáveis, a partir do cultivo in vitro de células da mucosa bucal, abre novas perspectivas de utilização, não se restringindo somente ao seu local de origem, ou seja, a boca, mas também como material de reconstrução para outras regiões, tais como: uretra, córnea, superfície ocular e epitélio córneo-limbal. Os métodos utilizados para a obtenção dessas células ainda são controversos na literatura. Neste sentido, avaliamos e comparamos a eficiência de dois métodos, enzimático e explante, para a obtenção de queratinócitos de mucosa bucal humana. Os fragmentos utilizados para a obtenção dessas células foram obtidos durante procedimentos cirúrgicos de pacientes voluntários saudáveis. Os queratinócitos foram cultivados sobre uma camada de sustentação, feeder-layer, confeccionada com fibroblastos murinos irradiados (3T3 - Swiss albino). Neste estudo foram comparados: o tempo para a obtenção dos queratinócitos, o rendimento obtido entre os dois métodos, a duração da vida útil em cultura, a capacidade que estas células tiveram em formar um epitélio in vitro e a morfologia dos mesmos. Os resultados obtidos, na avaliação dos dois métodos, comprovaram a possibilidade de obtenção dos queratinócitos, a partir de um pequeno fragmento bucal, porém pode-se verificar que existem vantagens e restrições peculiares a cada um dos métodos estudados. / The therapeutic procedures frequently used in oral treatments for the pathological diseases are surgical, resulting in failures of the mucosal continuity.The possibility to obtain transplantable oral epithelia from an in vitro cell culture opens new utilization perspectives not only to where it comes from, but also as a reconstructive matherial for other parts of the human body, such as: urethra, epithelia corneo-limbal, cornea, ocular surface. Many researchers still use controversial methods for obtaining cells. It was therefore evaluated and compared the efficiency in both methods: enzimatic and direct explant to obtain oral keratinocytes from human oral mucosa. Fragments of intra oral epithelial tissues from healthy human subjects, undergoing dental surgeries, were donated to the research project. The keratinocytes were cultivated over a feeder-layer from a previously irradiated 3T3 Swiss albino fibroblasts. In this study it was compared the time needed in the cell obtaintion, the best cell amount between both methods, the life-span, the cell capacity to form an in vitro epithelia and its morphologic structure. The results in the accessment of both methods have shown the possibility to obtain keratinocytes from a small oral fragment, but at the same time we may verify the advantages and peculiar restrictions for each one of both analyzed methods.

Fong Shu Pan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 147-167). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.i / LIST OF PUBLICATIONS --- p.ii / ABSTRACT --- p.iii / ABSTRACT [IN CHINESE] --- p.vii / TABLE OF CONTENT --- p.ix / LISTS OF FIGURES --- p.xv / LIST OF TABLES --- p.xxi / LIST OF ABBREVATIONS --- p.xxii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Embryonic stem (ES) cells --- p.1 / Chapter 1.2 --- Stem cell plasticity --- p.5 / Chapter 1.2.1 --- Differentiation and trans-differentiation of lineage-restricted stem cells --- p.5 / Chapter 1.2.1.1 --- Multilineage differentiation in-vitro --- p.5 / Chapter 1.2.1.2 --- Trans-differentiation --- p.6 / Chapter 1.2.2 --- Prospective applications of stem cells --- p.7 / Chapter 1.2.2.1 --- Basic research on development --- p.7 / Chapter 1.2.2.2 --- Study of human disease --- p.7 / Chapter 1.2.2.3 --- Cancer research --- p.7 / Chapter 1.2.2.4 --- Drug screening --- p.8 / Chapter 1.2.2.5 --- Cell therapy --- p.8 / Chapter 1.3 --- Neuro-degenerative diseases and cell therapy --- p.9 / Chapter 1.3.1 --- Neuro-degenerative diseases --- p.9 / Chapter 1.3.2 --- Neuro-regeneration --- p.10 / Chapter 1.3.3 --- Cell sources for neuro-regenerative therapy --- p.11 / Chapter 1.3.3.1 --- Comparison of stem cells --- p.11 / Chapter 1.3.3.2 --- Stem cells in neuro-regenerative therapy --- p.12 / Chapter 1.4 --- In-vitro derivation into neural lineage --- p.17 / Chapter 1.4.1 --- In-vitro induction strategies available --- p.17 / Chapter 1.4.1.1 --- Chemical agents --- p.18 / Chapter 1.4.1.1.1 --- Retinoic acid (RA) --- p.18 / Chapter 1.4.1.1.2 --- Ascorbic acid --- p.19 / Chapter 1.4.1.2 --- Growth factors/cytokines --- p.19 / Chapter 1.4.1.2.1 --- Neurotrophins --- p.20 / Chapter 1.4.1.2.2 --- Stimulants --- p.20 / Chapter 1.4.1.2.3 --- Signalling molecules --- p.21 / Chapter 1.4.1.3 --- Culture Selection --- p.23 / Chapter 1.4.1.3.1 --- Conditions --- p.23 / Chapter 1.4.1.3.2 --- Medium --- p.23 / Chapter 1.4.1.4 --- Transfection of regulator genes using viral vector --- p.24 / Chapter 1.4.1.5 --- Stromal cell-derived inducing activity (SDIA) --- p.26 / Chapter Chapter 2 --- Aims --- p.28 / Chapter 2.1 --- Hypothesis and study objectives --- p.28 / Chapter 2.1.1 --- Soliciting an optimal method for ES cell propagation --- p.28 / Chapter 2.1.2 --- Pursuing alternative SDIA --- p.29 / Chapter Chapter 3 --- Materials and Methods --- p.33 / Chapter 3.1 --- Chemicals and Reagents --- p.33 / Chapter 3.1.1 --- Cell Culture --- p.33 / Chapter 3.1.2 --- Immunohistochemistry and staining --- p.35 / Chapter 3.1.3 --- Molecular Biology --- p.36 / Chapter 3.2 --- Consumable --- p.37 / Chapter 3.3 --- Cell lines --- p.39 / Chapter 3.3.1 --- Feeder cells --- p.39 / Chapter 3.3.1.1 --- Primary mouse embryonic fibroblasts --- p.39 / Chapter 3.3.1.2 --- STO --- p.39 / Chapter 3.3.1.3 --- L Cells --- p.40 / Chapter 3.3.1.4 --- L-Wnt-3A Cells --- p.40 / Chapter 3.3.1.5 --- C17.2 --- p.40 / Chapter 3.3.2 --- ES cells --- p.41 / Chapter 3.3.2.1 --- ES-D3 --- p.41 / Chapter 3.3.2.2 --- ES-E14TG2a --- p.41 / Chapter 3.4 --- In-house prepared solutions --- p.42 / Chapter 3.4.1 --- "Stock solution of Insulin, Transferrin, Selentine (ITS) Supplement" --- p.42 / Chapter 3.4.2 --- Enriched Knock-Out Dulbecco's Modified Eagle's Medium (KO DMEM) --- p.42 / Chapter 3.4.3 --- Mitomycin C solution --- p.42 / Chapter 3.4.4 --- Gelatin solution 0.1% --- p.42 / Chapter 3.4.5 --- p-mercaptoethanol solution --- p.43 / Chapter 3.4.5.1 --- (3-mercaptoethanol solution 0.1M --- p.43 / Chapter 3.4.5.2 --- P-mercaptoethanol solution 0.1M --- p.43 / Chapter 3.4.5.3 --- p-mercaptoethanol solution 0.1M for preparation of culture medium --- p.43 / Chapter 3.4.6 --- ALL-trans retinoic acid --- p.43 / Chapter 3.4.6.1 --- ALL-trans retinoic acid stock solution 0.01M --- p.43 / Chapter 3.4.6.2 --- ALL-trans retinoic acid working solution lμM --- p.43 / Chapter 3.4.7 --- Paraformaldehyde solution 4% (PFA) --- p.44 / Chapter 3.4.8 --- TritoxX-100 solution --- p.44 / Chapter 3.4.8.1 --- Tritox X-100 solution 3% --- p.44 / Chapter 3.4.8.2 --- Tritox X-100 solution 0.3% --- p.44 / Chapter 3.4.9 --- Popidium iodide solution lug/mL (PI) --- p.44 / Chapter 3.4.10 --- Geneticin solution --- p.45 / Chapter 3.4.10.1 --- Geneticin solution 50mg/mL --- p.45 / Chapter 3.4.10.2 --- Geneticin solution 5mg/mL --- p.45 / Chapter 3.4.11 --- Poly-L-ornithine solution --- p.45 / Chapter 3.4.12 --- Laminin solution --- p.45 / Chapter 3.4.13 --- Maintenance medium for cell feeders --- p.46 / Chapter 3.4.14 --- Mitomycin C inactivation medium --- p.46 / Chapter 3.4.15 --- Freezing medium --- p.46 / Chapter 3.4.16 --- Propagation medium for ES cells --- p.47 / Chapter 3.4.16.1 --- Serum-based propagation medium for ES cells --- p.47 / Chapter 3.4.16.2 --- Serum-free propagation medium for ES cells --- p.47 / Chapter 3.4.16.3 --- Serum-free induction medium for ES cells --- p.48 / Chapter 3.4.16.3.1 --- Serum-free induction medium 1 --- p.48 / Chapter 3.4.16.3.2 --- Serum-free induction medium II --- p.48 / Chapter 3.4.16.3.3 --- Serum-free induction medium III --- p.48 / Chapter 3.5 --- Equipments --- p.49 / Chapter 3.6 --- Methods --- p.50 / Chapter 3.6.1 --- Cell Culture --- p.50 / Chapter 3.6.1.1 --- Preparation of round cover-slips --- p.50 / Chapter 3.6.1.2 --- Gelatinization of tissue culture wares --- p.51 / Chapter 3.6.1.3 --- Poly-L-ornithine and laminin coating --- p.51 / Chapter 3.6.1.4 --- Thawing frozen cells --- p.51 / Chapter 3.6.1.5 --- Passage of adherent culture --- p.52 / Chapter 3.6.1.6 --- Cell count --- p.52 / Chapter 3.6.1.7 --- Cytospin --- p.53 / Chapter 3.6.1.8 --- Cell viability test --- p.53 / Chapter 3.6.1.9 --- Cryopreservation --- p.53 / Chapter 3.6.1.10 --- Preparation of primary mouse embryonic fibroblast (PMEF) --- p.54 / Chapter 3.6.1.11 --- Mitomycin C inactivation of feeder cells --- p.55 / Chapter 3.6.1.12 --- Gamma irradiation of various feeders --- p.55 / Chapter 3.6.1.13 --- Preparation of CM from feeder cells --- p.56 / Chapter 3.6.1.14 --- Propagation of ES cells in serum-based medium --- p.56 / Chapter 3.6.1.15 --- Propagation of ES cell in serum-free medium --- p.56 / Chapter 3.6.1.16 --- Neural differentiation using all-trans retinoic acid --- p.57 / Chapter 3.6.1.17 --- Stromal cells-derived inducing activity --- p.58 / Chapter 3.6.1.18 --- BrdU labeling of the cell products --- p.59 / Chapter 3.6.2 --- Molecular analysis --- p.60 / Chapter 3.6.2.1 --- RNA extraction --- p.60 / Chapter 3.6.2.2 --- RNA quantitation --- p.60 / Chapter 3.6.2.3 --- Reverse Transcription of the First Strand complementary DNA --- p.61 / Chapter 3.6.2.4 --- Polymerase chain reaction --- p.61 / Chapter 3.6.2.5 --- RNA Integrity Check --- p.66 / Chapter 3.6.2.6 --- Electrophoresis and visualization of gene products --- p.66 / Chapter 3.6.3 --- Immunofluoresent staining --- p.66 / Chapter 3.6.4 --- In-vivo studies --- p.69 / Chapter 3.6.4.1 --- Induction of cerebral ischaemia in mice --- p.69 / Chapter 3.6.4.2 --- Transplantation --- p.69 / Chapter 3.6.4.3 --- Assessment of learning ability and memory --- p.70 / Chapter 3.6.5 --- Histological analysis --- p.70 / Chapter 3.6.5.1 --- Animal sacrifice for brain harvest --- p.70 / Chapter 3.6.5.2 --- Cryosectioning --- p.71 / Chapter 3.6.5.3 --- Paraffin sectioning --- p.71 / Chapter 3.6.5.4 --- Haematoxylin and eosin staining --- p.72 / Chapter 3.7 --- Data analysis --- p.73 / Chapter Chapter 4 --- Results --- p.74 / Chapter 4.1 --- ES cell maintenance --- p.74 / Chapter 4.1.1 --- Serum effect --- p.74 / Chapter 4.1.2 --- Feeder effect --- p.79 / Chapter 4.1.3 --- Serum-free and feeder-free condition --- p.86 / Chapter 4.1.4 --- Overall effect --- p.89 / Chapter 4.2 --- ES cell Induction --- p.91 / Chapter 4.2.1 --- Retinoic acid --- p.91 / Chapter 4.2.2 --- Stromal cell-derived inducing activity --- p.96 / Chapter 4.2.2.1 --- Molecular characterization of candidate stromal cells --- p.96 / Chapter 4.2.2.2 --- Direct contact co-culture --- p.98 / Chapter 4.2.2.3 --- Non-contact co-culture --- p.100 / Chapter 4.2.2.4 --- Cultures in CM --- p.109 / Chapter 4.3. --- ES cell Differentiation --- p.115 / Chapter 4.4 --- In vivo study of ES cell-derived cell products --- p.117 / Chapter 4.4.1 --- Animal preparation --- p.117 / Chapter 4.4.2 --- Cell preparation --- p.117 / Chapter 4.4.3 --- Cell implantation --- p.117 / Chapter 4.4.4 --- Behaviour Monitoring --- p.121 / Chapter 4.4.5 --- Histology of cell-implanted brain --- p.125 / Chapter Chapter 5 --- Discussion --- p.129 / Chapter Chapter 6 --- Conclusion --- p.144 / References --- p.147

Digital microfluidics (DMF) has emerged in the past decade as a novel microfluidic paradigm. As a liquid handling technology, DMF facilitates the electrostatic manipulation of discrete nano- and micro- litre droplets across open electrode arrays providing the advantages of single sample addressability, automation, and parallelization. This thesis presents DMF advances toward improved functionality and compatibility for automated miniaturized cell culture in two and three dimensions. Through the development and integration of surface patterning techniques we demonstrate a virtual microwell method for high precision on-device reagent dispensing in one and two plate DMF geometries. These methods are shown to be compatible with two-dimensional culture of immortalized cell lines on ITO, primary cells on coated surfaces, and for co-culture assays. We further extrapolate this method for the formation of microgels on-demand where form micro scale hydrogel structures through passive dispensing in a wide array of geometries. With this system we interrogate three-dimensional cell culture models, specifically for the recapitulation of kidney epthelialization and the analysis of functional cardiac microgels.