We have studied the effect of interferon α (IFN-α) on MHC class II expression by human buccal epithelial cells (BEC), and mRNA expression by BEC and mucosal-associated mononuclear cells (MAMC). In 6 experiments, freshly collected BEC were suspended at a concentration of 1.0 x 105/ml in RPMI 1640 and incubated in the presence of 0-10000 IU/ml of human lymphoblastoid IFN-α (HuIFN-α). Zero and six hour samples were analyzed by single color flow cytometry using FITC-labeled murine IgG1 monoclonal antibody to HLA-DR. Preparations were also analyzed for expression of cytokine transcripts (IL-2 IL-4, IL-5, IL-6, IL-8, IFN-γ, GM-CSF) by reverse transcriptase polymerase chain reaction (RT-PCR). Increasing concentrations of IFN-α resulted in proportionate increases in the percentage of HLA-DR + BEC (r = 0.7897, p = 0.0627) and in the percentage of HLA-DR + staining at higher intensities (101 to 102 log fluorescence intensity) (LFI) (r = 0.40l0, p = 0.0424). The percentage of HLA-DR + BEC rose from a mean of 1.5% with no IFN-α to 7% with 10000 IU/ml IFN-α (p < 0.05). The percentage of HLA-DR + BEC staining at 101 to 102 LFI rose from a mean of 8.3% with no added IFN-α to 19.2% with 10000 IU/ml IFN-α (p <0.05). Unstimulated BEC constitutively expressed IL-8 and GM-CSF. IFN-α stimulated preparations also expressed IFN-γ, possibly due to the presence of MAMC, which comprised 2-9% of the total cell population. These data indicated that HuIFN-α upregulates MHC class II expression by human BEC, possibly by enhancing IFN-γ production by MAMC present in the culture preparations.

Many preterm infants require mechanical ventilation as life-saving therapy. However, ventilation-induced overpressure can result in lung diseases. Considering the lung as a viscoelastic material, positive pressure inside the lung results in increased hydrostatic pressure and tissue compression. To elucidate the effect of positive pressure on lung tissue mechanics and cell behavior, we mimic the effect of overpressure by employing an uniaxial load onto fetal and adult rat lungs with different deformation rates. Additionally, tissue expansion during tidal breathing due to a negative intrathoracic pressure was addressed by uniaxial tension. We found a hyperelastic deformation behavior of fetal tissues under compression and tension with a remarkable strain stiffening. In contrast, adult lungs exhibited a similar response only during compression. Young’s moduli were always larger during tension compared to compression, while only during compression a strong deformation-rate dependency was found. In fact, fetal lung tissue under compression showed clear viscoelastic features even for small strains. Thus, we propose that the fetal lung is much more vulnerable during inflation by mechanical ventilation compared to normal inspiration. Electrophysiological experiments with different hydrostatic pressure gradients acting on primary fetal distal lung epithelial cells revealed that the activity of the epithelial sodium channel (ENaC) and the sodium-potassium pump (Na,K-ATPase) dropped during pressures of 30 cmH2O. Thus, pressures used during mechanical ventilation might impair alveolar fluid clearance important for normal lung function.

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During 20th century main concern was to have sanitary water flowing through the tap. In 21st century constant supply of safe drinking water is common at any home in USA. Hence consumers pay attention to aesthetic quality of tap water. Odorous algal metabolites in source water and metals introduced to drinking water due to corrosion of pipes in the distribution system cause taste, odor and color problems, and result in complaints and perception of tap water as unhealthy. Millions of dollars are spent each year by water industry to address and prevent these issues. This research focused on some of the taste-and-odor issues associated with drinking water. First aim was to understand when geosmin, 2-MIB, and nonadienal become detectable, employing two-resistance mass transfer theory to determine the concentration of odorants in bathroom air. Results showed that water temperature and odorant concentration in water play an important role. Next focus was to develop an international odor standard to be used for training of sensory analysis panelists. There are many sensory methods to monitor drinking water to detect the off-flavors however an odor standard has been missing. Hexanal was studied with trained flavor profile analysis panels and was proposed as an ideal odor reference standard to be used for training and sensory assessment of water samples. Main focus was to understand metallic flavor of drinking water caused by iron and copper. It was shown that metallic sensation has taste and retronasal components creating the flavor and humans are very sensitive to it. Occurrence of lipid oxidation in the oral cavity was shown when metals were ingested, that produces carbonyls which are responsible for the metallic flavor. Antioxidants and chelators were investigated to study prevention of lipid oxidation and, chelators were determined to be more effective. Oral epithelial cell cultures were developed as a model for oral cavity to further investigate lipid oxidation and effectiveness of the antioxidants and chelators. This dissertation is a result of inter-disciplinary work and possibly a good example for how problems may be solved by incorporating different methods and point of views from several disciplines. / Ph. D.

La necesidad de polímeros bioestables para fabricación de implantes protésicos queda patente, entre otros indicadores, por la proliferación de dispositivos actualmente comercializados. La caracterización físico-química así como la respuesta biológica de un conjunto de materiales poliméricos bioestables es el objetivo último de esta tesis. En este trabajo se han sintetizado diferentes materiales poliméricos de la familia de los acrilatos y metacrilatos variando sutilmente sus características superficiales, como el grado de hidrofilia o la distribución de cargas eléctricas. El procedimiento consistió en la copolimerización via radical de acrilato de etilo, EA, acrilato de 2-hidroxietilo, HEA, y ácido metacrílico, MAAc. Se ha caracterizado los materiales en estado seco y en presencia de diferentes contenidos de agua mediante calorimetría diferencial de barrido, DSC, análisis dinámico-mecánico, DMA, microscopía de fuerza atómica, AFM, análisis dieléctrico, DRS, contenido de agua en equilibrio, EWC, y energía superficial, SE, persiguiendo el objetivo de dilucidar si el agua es capaz de inducir cambios conformacionales en las cadenas poliméricas que den lugar a una separación de fases. Sobre los materiales en forma de scaffold poroso con poros esféricos interconectados se ha cultivado fibroblastos y endoteliales. La compatibilidad de las células endoteliales se midió en términos de viabilidad celular y la adecuada diferenciación endotelial y su funcionamiento. Se han realizado cultivos de células endoteliales humanas primarias, HUVEC, y se ha determinado si su morfología y función se vio afectada por el material. Se examinó la adhesión y proliferación de las mismas, así como un marcador importante de activación endotelial, la E-selectina. Se evaluó si se mantuvieron los fenotipos endoteliales normales y sus funciones observadas in vivo mediante análisis de los contactos célula-célula y la regulación de la expresión génica del marcador de activación E-selectina cuando se añadió un estímulo (LPS). Además, como posible aplicación de estos materiales en una prótesis de córnea artificial, y dado que los fibroblastos del estroma de la córnea (es decir, los queratocitos) son de relevancia en la cicatrización de la córnea se determinó cómo afectaba la hidrofilicidad del substrato a la adhesión celular de la línea de fibroblastos humanos MRC-5, como modelo celular para estudiar la disposición del citoesqueleto tras la adhesión a los diferentes soportes mediante la detección de F-actina. Asimismo, se ha sembrado células epiteliales evaluando su comportamiento/funcionamiento celular ya que uno de los requisitos esenciales para que un implante de queratoprótesis tenga éxito es que se cree y mantenga una capa de células epiteliales que impidan entrar a las bacterias al interior del ojo y permita la difusión la capa lagrimal de manera estable en el tiempo. Así, se han analizado parámetros celulares como adhesión, proliferación y viabilidad de una línea de células epiteliales de conjuntiva humana, NHC, cultivada sobre substratos poliméricos con diferentes grados de hidrofilia y cargas eléctricas superficiales buscando qué grado de hidrofilicidad permite la epitelización del substrato y podría darle al material flexibilidad y la hidrofilicidad necesaria para un mejor contacto con los párpados y lágrima. Los resultados obtenidos se han correlacionado con la adsorción y conformación de una proteína de la matriz extracelular, la fibronectina. / Campillo Fernández, AJ. (2014). Polímeros bioestables para fabricación de implantes protésicos: caracterización físico-química y respuesta biológica in vitro [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/44232 / Premios Extraordinarios de tesis doctorales