Studies of clinically applicable human tolerogenic dendritic cells and PD-L2 genetic modification of human islet allograft to promote graft tolerance.

Islet transplantation is a developing therapy for type 1 diabetic patients (T1D), which has been limited by problems associated with hypoxia, poor revascularisation and allograft rejection. Immunosuppressive agents used to prevent rejection are associated with severe side effects including islet toxicity, increased susceptibility to the development of cancer, infections and cardio-vascular problems. In order for islet transplantation to be used widely as a potentially curative treatment for T1D there is a need to develop novel therapies to treat allograft rejection without the use of immunosuppressive agents. In chapter 3, the immunomodulatory effects of IFN-γ on human monocyte-derived DC were investigated, using a standard 7-day in vitro DC propagation protocol. IFN-γ was shown to exert its immunomodulatory function on monocytes early during DC differentiation (IFNγ-DC[subscript]D0), resulting in an immature DC (iDC) phenotype with reduced expression of maturation markers CD83 and RelB. IFNγ-DC[subscript]D0 induced a state of T-cell hyporesponsiveness in a MLR, whilst IFN-γ treatment at day 5 (IFNγ-DC[subscript]D5) did not modulate DC function. The ability of IFN-γ to promote the generation of maturation arrested DC, could potentially serve as a cellular therapy for transplant rejection. However DC propagation using the standard 7-10 day protocol is not clinically applicable in the islet transplant setting. In chapter 4, a 'FAST-DC' protocol to promote the rapid generation of tolerogenic DC was investigated and used to generate IFNγ modulated DC in 48h. These IFNγ-DC featured an iDC phenotype similar to that seen in chapter 3. Maturation arrested IFNγ-DC caused significant T-cell hyporesponsiveness and promoted a higher frequency of CD4+CD25+ Foxp3[superscript]HI T-regulatory cells. IFNγ-DC primed T-cells were shown to be functionally suppressive in an antigen specific manner. It was also confirmed that IFN-γ reduced the phosphorylation of IL-4 activated STAT-6, which in turn affected the downstream gene expression of Interferon regulatory factor 4 (IRF4). IFNγ-DC were also investigated in vivo, where a humanised model of islet allo-transplantation model was developed. Diabetic NOD-SCID mice were transplanted with human islets and challenged with donor-derived DC and allogeneic PBMNC. After 21 days post transplantation, there was no significant change to euglycaemic state, between the tested groups. Genetic modification of the allograft is an alternative therapy to protecting the graft from the recipient‟s immune system. In chapter 5, human islets were genetically modified with programmed cell death ligand 2 (PD-L2), an inhibitory molecule known inhibit T-cell immune responses. Two recombinant adenovirus constructs carrying the PD-L2 gene were generated. One construct encoded a soluble isoform, while the other expressed a full transmembrane PD-L2 molecule. Adenoviral transduction did not affect the viability or insulin producing capacity of islets. Interestingly, soluble PD-L2 was more efficient at inducing signalling by 1000 fold, compared to the transmembrane isoform. In summary, this thesis demonstrated the timing of IFN-γ exposure is crucial in determining the function of DC and their maturational state, where IFN-γ exposure only during DC differentiation resulted in the inhibition of DC maturation. Secondly, the combination of IFN-γ and a FAST-DC protocol, enabled the generation of tolerogenic DC in 48h, making DC therapy more clinically applicable. Finally, the induced expression of soluble PD-L2 by human islets potently signals through human PD-1, which may provide the basis for the protection of islets from allo- and auto T-cell responses.Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 201

Estudio de prevalencia de quistes hidatidícos en pacientes con resección quirúrgica del hospital regional de Talca

88 p.El estudio de los quistes hidatídicos cada vez, está llamando más la atención, puesto que el aumento de casos diagnosticados se ha acrecentado en los últimos años. La Hidatidosis es una zoonosis parasitaria de alta endemicidad en algunos países especialmente en algunos de América del Sur, sobre todo en Argentina, Chile, Uruguay y Brasil. Esta enfermedad está provocada por la ingesta causal de huevos de Echinococcus granulosus que, a menudo, pueden contaminar alimentos. Puede afectar a animales, tanto salvajes como domésticos, e incluso al ser humano. La Hidatidosis humana prevalece en el hígado, le sigue en frecuencia el pulmón, las otras localizaciones comunes son el peritoneo, bazo, riñón, huesos, corazón, piel y músculos. Se abordará aspectos epidemiológicos de la Hidatidosis tanto en América del Sur. Resaltando la situación de esta parasitosis en Chile, evaluando puntos tales como la prevalencia a través de los años, y así mismo las regiones con mayor endemicidad. En la Región del Maule se ha mantenido la prevalencia de esta parasitosis, por su característica de Región agrícola y ganadera, estos quistes hidatídicos se alojan en distintos órganos del ser humano. Por ende se realizó un estudio para determinar cuál es la situación actual de casos, y los órganos más prevalentes en la Provincia de Talca. Para ello se recogieron antecedentes de pacientes registrados en la Unidad de Anatomía Patológica del Hospital Regional de Talca, y se realizó un análisis de la base de datos comprendido entre los años 2000 y 2010. Al analizar los datos obtenidos, se puede concluir que la Hidatidosis en la Provincia de Talca sigue tan prevalente, como hace 10 años atrás, registrándose que el órgano más común infectado tanto para el hombre como para la mujer sigue siendo el hígado, además existe una alta prevalencia de quistes localizados en la zona del sistema reproductor femenino

Modelo de gestión de costos para proyectos en empresas de servicio en tecnologías de información.

Proyecto de Graduación (Maestría en Gerencia de Proyectos Empresariales) Instituto Tecnológico de Costa Rica, Escuela de Administración de Empresas, Escuela de Ingeniería en Construcción, Escuela de Ingeniería en Computación, 2011.Currently, most information technology service companies develop solutions to solve problems and meet the needs of customers through project implementation. Project management has gradually evolved in a positive way in different areas. However, the cost management issue still has many flaws that require not only a process visualization of the costs, but a systemic visualization, taking into account interactions with other areas of organizational support. This study offers an alternative solution to the cost management deficiency, through a model that considers the costs of the processes involved and additionally takes into account the unique characteristics specific to the organization. Finally, it provides a support tool, which in its first version can be used to track and follow up costs, ensuring that they align with the terms of the proposed model.Instituto Tecnológico de Costa Rica

Gestión educativa y participación de padres de familia durante el COVID-19 en el distrito de Ate

La presente investigación titulada: “Gestión educativa y participación de padres de familia durante el COVID-19 en el distrito de Ate”, tuvo como objetivo analizar la gestión educativa y las consecuencias que está ocasionando en la participación de los padres de familia de dos instituciones educativas del distrito de Ate. El tipo de investigación fue básica, el diseño fenomenológico, el enfoque fue cualitativo, la muestra estuvo conformada por seis padres de familia, tres de una escuela pública y tres de un colegio privado; los instrumentos empleados fueron la entrevista semiestructurada y la observación, las conclusiones que se obtuvieron fueron que la gestión educativa viene afectando la participación de los padres de familia en el distrito de Ate, a partir del cierre de las escuelas por cerca de dos años, como parte de la aplicación de una política pública que se orientó a evitar la propagación de la pandemia y que ha ido en desmedro de los estudiantes y sus familias

El sistema de elección de magistrados del Tribunal Constitucional peruano: un análisis crítico y reflexivo

Esta tesis ofrece un estudio acerca del sistema de elección de magistrados del Tribunal Constitucional peruano. Para ello se inicia reflexionando sobre el papel que tuvieron los jueces con el liberalismo constitucional del siglo XVIII, a partir de la separación de poderes planteada por el barón de Montesquieu y de los innovadores aportes del constitucionalismo estadounidense, posteriormente se comenta sobre el cambio de paradigma que supuso la creación de Tribunales Constitucionales y el empoderamiento del magistrado constitucional en el siglo XX, así como también sobre las dificultades teóricas resultantes. En la segunda parte, se examina la legislación comparada para dilucidar como distintos países han adecuado sus respectivos sistemas de elección para garantizar la integridad e independencia en sus magistrados. En la tercera parte, se describe la fuente normativa aplicable al caso peruano y se elabora un recuento de todos los procesos de elección llevados a cabo en nuestro país. En la cuarta parte se proponen recomendaciones en base a un análisis crítico. Y finalmente se cierra la presente investigación con conclusiones.This thesis offers a study of the system for the election of magistrates in the Peruvian Constitutional Court. It begins by reflecting on the role of judges in the constitutional liberalism of the 18th century, based on the separation of powers proposed by Baron de Montesquieu and the innovative contributions of U.S. constitutionalism; and then comments on the paradigm shift brought about by the creation of Constitutional Courts and the empowerment of the constitutional judge in the 20th century, as well as the resulting theoretical difficulties. In the second part, comparative legislation is examined to elucidate how different countries have adapted their respective election systems to guarantee the integrity and independence of their magistrates. In the third part, the normative source applicable to the Peruvian case is described and an account of all the election processes carried out in our country is elaborated. The fourth part proposes recommendations based on a critical analysis. And finally, the present research closes with conclusions.Tesi

Immunodepletion and hypoxia preconditioning of mouse vompact bone cells as a novel protocol to isolate highly immunosuppressive mesenchymal stem cells

Prepublished on Liebert Instant Online December 21, 2016Compact bones (CB) are major reservoirs of mouse mesenchymal stem cells (mMSC). Here, we established a protocol to isolate MSC from CB and tested their immunosuppressive potential. Collagenase type II digestion of BM-flushed CB from C57B/6 mice was performed to liberate mMSC precursors from bone surfaces to establish nondepleted mMSC. CB cells were also immunodepleted based on the expression of CD45 (leukocytes) and TER119 (erythroid cells) to eliminate hematopoietic cells. CD45-TER119- CB cells were subsequently used to generate depleted mMSC. CB nondepleted and depleted mMSC progenitors were cultured under hypoxic conditions to establish primary mMSC cultures. CB depleted mMSC compared to nondepleted mMSC showed greater cell numbers at subculturing and had increased functional ability to differentiate into adipocytes and osteoblasts. CB depleted mMSC had high purity and expressed key mMSC markers (>85% Sca-1, CD29, CD90) with no mature hematopoietic contaminating cells (<5% CD45, CD11b) when subcultured to passage 5 (P5). Nondepleted mMSC cultures, however, were less pure and heterogenous with <72% Sca-1+, CD29+, and CD90+ cells at early passages (P1 or P2), along with high percentages of contaminating CD11b+ (35.6%) and CD45+ (39.2%) cells that persisted in culture long term. Depleted and nondepleted mMSC nevertheless exhibited similar potency to suppress total (CD3+), CD4+ and CD8+ T cell proliferation, in a dendritic cell allostimulatory one-way mixed lymphocyte reaction. CB depleted mMSC, pretreated with proinflammatory cytokines IFN-γ, TNF-α, and IL-17A, showed superior suppression of CD8+ T cell, but not CD4+ T cell proliferation, relative to untreated-mMSC. In conclusion, CB depleted mMSC established under hypoxic conditions and treated with selective cytokines represent a novel source of potent immunosuppressive MSC. As these cells have enhanced immune modulatory function, they may represent a superior product for use in clinical allotransplantation.Kisha Nandini Sivanathan, Stan Gronthos, Shane T. Grey, Darling Rojas-Canales, and Patrick T. Coate

Transcriptome profiling of IL-17A preactivated mesenchymal stem cells: a comparative study to unmodified and IFN-gamma modified mesenchymal stem cells

Published 15 February 2017Human mesenchymal stem cells pretreatment with IL-17A (MSC-17) potently enhances T cell immunosuppression but not their immunogenicity, in addition to avidly promoting the induction of suppressive regulatory T cells. The aim of this study was to identify potential mechanisms by which human MSC-17 mediate their superior immunomodulatory function. Untreated-MSC (UT-MSC), IFN-γ treated MSC (MSC-γ), and MSC-17 were assessed for their gene expression profile by microarray. Significantly regulated genes were identified for their biological functions (Database for Annotation, Visualisation and Integrated Discovery, DAVID). Microarray analyses identified 1278 differentially regulated genes between MSC-γ and UT-MSC and 67 genes between MSC-17 and UT-MSC. MSC-γ were enriched for genes involved in immune response, antigen processing and presentation, humoral response, and complement activation, consistent with increased MSC-γ immunogenicity. MSC-17 genes were associated with chemotaxis response, which may be involved in T cell recruitment for MSC-17 immunosuppression. MMP1, MMP13, and CXCL6 were highly and specifically expressed in MSC-17, which was further validated by real-time PCR. Thus, MMPs and chemokines may play a key role in mediating MSC-17 superior immunomodulatory function. MSC-17 represent a potential cellular therapy to suppress immunological T cell responses mediated by expression of an array of immunoregulatory molecules.Kisha Nandini Sivanathan, Darling Rojas-Canales, Shane T. Grey, Stan Gronthos, and Patrick T. Coate

Satisfacción de los productores sobre la producción orgánica: estudio de caso rubro berries regiones del Maule y del Bio-Bío

65 p.El mercado de la Agricultura Orgánica, en Chile y el mundo, ha sido uno de los sectores de mayor crecimiento en los últimos años; debido principalmente al conocimiento de los beneficios ambientales que este tipo de agricultura presenta y a la notable demanda de productos orgánicos por parte de consumidores más sensibilizados frente a los problemas ambientales. La Agricultura Orgánica se presenta como uno de los enfoques más sostenibles en la producción de alimentos, pero la sostenibilidad en el tiempo depende en gran parte a la adopción y satisfacción por parte de los agricultores. En este contexto, el propósito de esta investigación fue analizar los factores que determinan el nivel de satisfacción de los productores respecto la Agricultura Orgánica en Chile. Para ello se evaluó y caracterizó a agricultores involucrados en el sistema orgánico. Se aplicó una encuesta dirigida a 60 productores de berries orgánicos, en las regiones del Maule y del Bio-Bío, entre los meses noviembre de 2011 y abril de 2012. Para el análisis de resultados se utilizó la metodología de estadística descriptiva y de Análisis Logístico Binario, lo que permitió caracterizar a productores, en función de su motivación para el ingreso al sistema orgánico como así también, determinar el nivel de satisfacción respecto a la rentabilidad en el negocio orgánico y las variables que influyen en ésta. Entre los principales resultados se encuentran la directa relación entre motivación de ingreso por temas no económicos con el uso de prácticas de conservación como reciclaje de nutriente y diversificación biótica. En relación a la satisfacción con la rentabilidad en el negocio orgánico, se observa que ésta depende principalmente de los ingresos, tamaño predial, uso de insumos externos y rendimiento predial. La investigación desarrollada presenta importantes indicadores del perfil de productores que se encuentran en el sistema orgánico, lo cual pretende ser de gran ayuda para el establecimiento de futuras políticas en el ámbito de la Agricultura Orgánica. Palabras claves: satisfacción, motivación, Agricultura Orgánica, berries./ABSTRACT :The market of Organic Agriculture in Chile and the world has been one of the fastest growing sectors in recent years due to the knowledge of the environmental benefits that this type of agriculture has and the strong demand for organic products by consumers sensitive to environmental problems. Organic agriculture is presented as one of the most sustainable approaches within the food production, but sustainability over time largely depends on the adoption and satisfaction of farmers. In this context, the purpose of this research was to analyze the factors that determine the level of satisfaction of the producers of Organic Agriculture in Chile. To do this, farmers involved in the organic system were evaluated and characterized. A survey was conducted at 60 producers of organic berries in the regions of Maule and Bio-Bio, during the months November 2011 and April 2012. To analyze results, the methodology of descriptive statistics and binary logistic analysis was used, which allowed producers to be characterized in terms of their motivation to join the organic system also determine the level of satisfaction regarding profitability on the organic production business and the variables influencing it. The main results are the direct link between motivation to be a part of an organic production system (for noneconomic factors) with the use of conservation practices such as recycling of nutrients and biotic diversification. In relation to satisfaction of profitability in the organic business, it was noted that this depends primarily on income, farm size, use of external inputs and farm yield. The research presents significant indicators profile producers who are part of the organic system, which aims to be helpful for the establishment of future policies in the field of Organic Agriculture. Keywords: satisfaction, motivation, Organic Agriculture, berries