307 research outputs found

    Characterization of murine pancreatic carcinoma models regarding immunosuppressive mechanisms and therapy with bifunctional siRNA targeting galectin-1

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    Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive tumor that is characterized by abundant tumor stroma and a potent immunosuppressive microenvironment. Further studies to clarify why T cells infiltrate the tumor but are not able to perform effector functions as well as to find new effective therapies to overcome immunosuppression are urgently needed. The aims of the present study were (1) to characterize different murine PDAC tumor models in regard to their utility for studying novel immunotherapeutic approaches, (2) to assess the therapeutic efficacy of a novel bifunctional ppp-siRNA that combines silencing of the immunosuppressive molecule galectin-1 and RIG-I-mediated immune activation in murine PDAC and (3) to characterize the immunosuppressive mechanisms leading to T cell inhibition in the tumor microenvironment. (1) This study revealed that the pancreatic cancer cell line T110299, which was developed from a primary tumor of the KPC mouse model, is a new valuable tool for studying novel treatment strategies for PDAC. The histological appearance of T110299 tumors reflects in many aspects the primary tumors in KPC mice, which harbor mutations in the Kras oncogene and p53, and the human disease with regard to tumor differentiation, extensive tumor stroma development, poor vascularization and expression of immunosuppressive molecules, like indoleamine 2,3-dioxygenase (IDO) and galectin-1 (Gal-1). In contrast, Panc02 tumors were found to have a sarcomatoid architecture with very little tumor stroma. In Panc02 cells, galectin-1 was strongly expressed by the tumor cells, which differs from the situation found in humans, KPC mice and T110299 tumors, where galectin-1 is preferentially expressed in tumor-associated pancreatic stellate cells (PSC). However, expression of the cytosolic helicase RIG-I was functional in Panc02 cells, but defective in T110299 cells. As RIG-I is expressed in all human PDAC cell lines tested, the Panc02 model appears to be better suited to study RIG-I-based immunotherapies (Ellermeier et al., 2013). Thus, the histological and functional characterization of the tumor models in this thesis will allow selecting the best-suited tumor model for addressing specific aspects of immunotherapy. (2) Treatment studies of PDAC were performed with the 5’ppp-modified siRNA molecule ppp-Gal-1 in the orthotopic Panc02 tumor model. The dual activities of this molecule were confirmed in vitro, leading to (i) reduced galectin-1 expression via RNAi; and (ii) production of CXCL10 and IFN-, MHC-I up-regulation and apoptosis of tumor cells via RIG-I activation. Treatment of mice with orthotopic pancreatic tumors with ppp-Gal-1 significantly prolonged survival, as compared to unmodified OH-Gal-1 or control RNA. In addition, 20% of the mice completely rejected their tumors leading to long-term tumor control. Thus, bifunctional 5’ppp-modified siRNA is a promising treatment strategy for PDAC deserving further pre-clinical evaluation. (3) Pancreatic tumor cells employ multiple mechanisms for suppression of T cell responses. This study identified TGF-β and IDO as two potent mechanisms leading to inhibition of T cell proliferation. Minute amounts of PDAC supernatants effectively blocked T cell proliferation induced by CD3 and CD28 triggering. This could be partially prevented by SD-208, a small molecule inhibitor of TGF-β receptor signaling, or by blocking IDO activity with D-1-MT. Interestingly, tumor supernatants induced up-regulation of IDO mRNA expression in T cells. Furthermore, blocking IDO activity in T cells appeared to be more effective than blocking IDO in tumor cells. This leads to a new hypothesis that factors secreted by the tumor cells induce IDO expression in T cells, which in turn leads to auto-intoxication of the T cells via kynurenine production and eventually T cell apoptosis. Further studies confirming this hypothesis are warranted

    Educating a creative engineer: learning from engineering professionals

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    The rapid growth of engineering knowledge has resulted in continuous expansion of novel technologies and materials that can be used in designing new products and processed. Computer- and web-based technologies allowed engineers to significantly shorten the development of novel artefacts. These advances intensified the competition between engineering companies and shortened the lifespans of the majority of engineering products. As a result, practicing engineers are now expected to deliver creative designs to markets much more swiftly than ever before. This paper presents the results of a survey that intended to establish the ways and the means of enhancing engineering creativity that suit the engineering industry of the 21st Century. This study engaged 46 engineering experts from the major international corporations who utilised numerous creativity techniques including TRIZ in their day-to-day engineering work. It had been found that the surveyed engineering experts think that in the current Information age (i) knowledge beyond engineering profession is more important for creativity than the discipline knowledge; (ii) learning creativity methods and problem solving heuristics is more important than acquiring additional discipline knowledge; (iii) the problem solving stage of identifying and understanding a problem is the key to a creative solution

    Characterization of murine pancreatic carcinoma models regarding immunosuppressive mechanisms and therapy with bifunctional siRNA targeting galectin-1

    Get PDF
    Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive tumor that is characterized by abundant tumor stroma and a potent immunosuppressive microenvironment. Further studies to clarify why T cells infiltrate the tumor but are not able to perform effector functions as well as to find new effective therapies to overcome immunosuppression are urgently needed. The aims of the present study were (1) to characterize different murine PDAC tumor models in regard to their utility for studying novel immunotherapeutic approaches, (2) to assess the therapeutic efficacy of a novel bifunctional ppp-siRNA that combines silencing of the immunosuppressive molecule galectin-1 and RIG-I-mediated immune activation in murine PDAC and (3) to characterize the immunosuppressive mechanisms leading to T cell inhibition in the tumor microenvironment. (1) This study revealed that the pancreatic cancer cell line T110299, which was developed from a primary tumor of the KPC mouse model, is a new valuable tool for studying novel treatment strategies for PDAC. The histological appearance of T110299 tumors reflects in many aspects the primary tumors in KPC mice, which harbor mutations in the Kras oncogene and p53, and the human disease with regard to tumor differentiation, extensive tumor stroma development, poor vascularization and expression of immunosuppressive molecules, like indoleamine 2,3-dioxygenase (IDO) and galectin-1 (Gal-1). In contrast, Panc02 tumors were found to have a sarcomatoid architecture with very little tumor stroma. In Panc02 cells, galectin-1 was strongly expressed by the tumor cells, which differs from the situation found in humans, KPC mice and T110299 tumors, where galectin-1 is preferentially expressed in tumor-associated pancreatic stellate cells (PSC). However, expression of the cytosolic helicase RIG-I was functional in Panc02 cells, but defective in T110299 cells. As RIG-I is expressed in all human PDAC cell lines tested, the Panc02 model appears to be better suited to study RIG-I-based immunotherapies (Ellermeier et al., 2013). Thus, the histological and functional characterization of the tumor models in this thesis will allow selecting the best-suited tumor model for addressing specific aspects of immunotherapy. (2) Treatment studies of PDAC were performed with the 5’ppp-modified siRNA molecule ppp-Gal-1 in the orthotopic Panc02 tumor model. The dual activities of this molecule were confirmed in vitro, leading to (i) reduced galectin-1 expression via RNAi; and (ii) production of CXCL10 and IFN-, MHC-I up-regulation and apoptosis of tumor cells via RIG-I activation. Treatment of mice with orthotopic pancreatic tumors with ppp-Gal-1 significantly prolonged survival, as compared to unmodified OH-Gal-1 or control RNA. In addition, 20% of the mice completely rejected their tumors leading to long-term tumor control. Thus, bifunctional 5’ppp-modified siRNA is a promising treatment strategy for PDAC deserving further pre-clinical evaluation. (3) Pancreatic tumor cells employ multiple mechanisms for suppression of T cell responses. This study identified TGF-β and IDO as two potent mechanisms leading to inhibition of T cell proliferation. Minute amounts of PDAC supernatants effectively blocked T cell proliferation induced by CD3 and CD28 triggering. This could be partially prevented by SD-208, a small molecule inhibitor of TGF-β receptor signaling, or by blocking IDO activity with D-1-MT. Interestingly, tumor supernatants induced up-regulation of IDO mRNA expression in T cells. Furthermore, blocking IDO activity in T cells appeared to be more effective than blocking IDO in tumor cells. This leads to a new hypothesis that factors secreted by the tumor cells induce IDO expression in T cells, which in turn leads to auto-intoxication of the T cells via kynurenine production and eventually T cell apoptosis. Further studies confirming this hypothesis are warranted

    Matemática II-EGB 3 : proyecto pedagógico con modalidad a distancia para la terminalidad de estudios de EGB3 y Educación Polimodal EDITEP

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    El presente libro propone profundizar lo aprendido anteriormente en el área de Matemática y avanzar en el aprendizaje de nuevos conceptos y procedimientos. Al final de este curso esperamos que el alumno pueda identificar, interpretar y utilizar, en la resolución de problemas, algunos conceptos matemáticos relacionados con: los números racionales, sus cálculos y operaciones, figuras planas y tridimensionales, las medidas y la medición, los gráficos y los distintos lenguajes matemáticos. Se editó como material de aprendizaje destinado al personal de seguridad pública de la Provincia de Mendoza en el marco del proyecto pedagógico con modalidad a distancia para la terminalidad de estudios de EGB3 y Educación Polimodal –EDITEP–, implementado a partir de la firma del Convenio entre la Universidad Nacional de Cuyo y el Gobierno de la Provincia de Mendoza, en octubre de 2003

    Matemática I - Polimodal : proyecto pedagógico con modalidad a distancia para la terminalidad de estudios de ECB3 y Educación Polimodal EDITEP

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    Este libro busca que el lector identifique e interprete conocimientos referidos a números reales y a sus operaciones, reconociendo los algoritmos y los procedimientos relacionados vinculándolos al cálculo de distintas medidas; que comprenda y sepa resolver problemas, seleccionando el tipo de razonamiento o argumentación que requiera la situación; que emplee sistemas de ecuaciones e inecuaciones para modelizar y resolver situaciones reales del entorno cotidiano; y que identifique, defina, grafique, describe e interprete distintos tipos de funciones asociándolas a situaciones reales. Se editó como material de aprendizaje destinado al personal de seguridad pública de la Provincia de Mendoza en el marco del proyecto pedagógico con modalidad a distancia para la terminalidad de estudios de EGB3 y Educación Polimodal –EDITEP–, implementado a partir de la firma del Convenio entre la Universidad Nacional de Cuyo y el Gobierno de la Provincia de Mendoza, en octubre de 2003

    New Forensic Insight into Carl Auer von Welsbach's 1910 Observation of Induced Radioactivity: Theoretical, Experimental and Historical Approaches

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    In 1910, Carl Auer von Welsbach noted that he had made an observation of a radioactive substance inducing radioactivity to an inactive substance. From today's point of view, this could have been the first observation of neutron activation. Herein, we present new insights into our investigation of this ‘mysterious observation’ as Auer von Welsbach termed it. We believe that one of the activated objects was a platinum–iridium crucible. The dominating activation product of the crucible could have been iridium-194. We have discovered several platinum crucibles from Auer's heritage and investigated them by gamma-spectrometry and, one of them, by SEM/EDX. In the EDX investigations, however, no iridium was found in the most promising crucible. Hence this particular crucible was probably not the activated object. In any case, gamma-ray spectrometry revealed very low but detectable amounts of natural radionuclides. This indicated that these crucibles were used by Auer von Welsbach for his radioactive work and that these crucibles were bought prior to World War I. Hence Auer von Welsbach somehow managed to save these crucibles from the noble metal collections during the war. Auer's 1910 publication carried the suffix ‘Part I’, however, Part II was thought to be lost. In our recent work, however, we rediscovered a hand-written manuscript of Part II, in which the peculiar observation is mentioned vaguely. Lastly, we converted Auer's uranium standard into becquerels. Based on this conversion, we estimated that Auer von Welsbach observed an 194Ir activity of the crucible of 500 kBq. It is further estimated that a (thermal) neutron flux density of approximately 8E+4 cm−2 s−1 was needed to activate the crucible in a way to meet Auer's description. This is an Accepted Manuscript of an article published by Taylor & Francis in Interdisciplinary Science Reviews on 2017-01-09, available online: http://www.tandfonline.com/doi/full/10.1080/03080188.2016.1251731

    Langzeiterfahrungen mit der ipsilateralen Elektroakustischen Stimulation (EAS) : meeting abstract

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    Hochgradig hörgeschädigten Patienten mit einem Tieftonrestgehör (Steilabfall im Audiogramm) können mittels ipsilateraler EAS versorgt werden. Dabei wird der völlig taube Hochfrequenzbereich des Innenohres mit einem Cochleaimplantat stimuliert, und die tieffrequente Restfunktion der Schnecke bleibt erhalten. Voraussetzung für eine derartige Versorgung ist ein Erhalt des tieffrequenten Restgehöres bei der Cochlea-Implant-Elektrodeneinführung. Im Rahmen einer klinischen Studie wurden seit 1999 in Frankfurt 25 Patienten mit EAS versorgt. Des Weiteren wurden 16 Patienten im Rahmen einer europäischen Multicenterstudie für EAS implantiert. Ein zumindest teilweiser Erhalt des Restgehöres war in über 90% der Fälle möglich. Es wird über die Langzeitergebnisse (6 bis 70 Monate) nach EAS-Implantation berichtet. In 70% der Fälle blieb das erhaltene Restgehör stabil. Die Patienten zeigten überdurchschnittlich gute Werte bei der Sprachdiskrimination mit ihren Cochleaimplantaten, die durch zusätzliche akustische Stimulation noch verbessert wurden. Besonders deutlich waren die Hörleistungen unter Störgeräuscheinfluss. Seit Kurzem steht auch ein kombinierter Sprachprozessor für die elektrische und akustische Stimulation zur Verfügung

    Matemática I - EGB3 : proyecto pedagógico con modalidad a distancia para la terminalidad de estudios de EGB3 y Educación Polimodal EDITEP

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    Este trabajo busca que el lector identifique, interprete y utilice, en la resolución de problemas, algunos conceptos matemáticos relacionados con los números enteros y racionales, sus cálculos y operaciones, rectas, ángulos y figuras, las medidas y la medición, los gráficos y los distintos lenguajes matemáticos. Se editó como material de aprendizaje destinado al personal de seguridad pública de la Provincia de Mendoza en el marco del proyecto pedagógico con modalidad a distancia para la terminalidad de estudios de EGB3 y Educación Polimodal –EDITEP–, implementado a partir de la firma del Convenio entre la Universidad Nacional de Cuyo y el Gobierno de la Provincia de Mendoza, en octubre de 2003

    Intraoperative electrocochleographic characteristics of auditory neuropathy spectrum disorder in cochlear implant subjects

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    Auditory neuropathy spectrum disorder (ANSD) is characterized by an apparent discrepancy between measures of cochlear and neural function based on auditory brainstem response (ABR) testing. Clinical indicators of ANSD are a present cochlear microphonic (CM) with small or absent wave V. Many identified ANSD patients have speech impairment severe enough that cochlear implantation (CI) is indicated. To better understand the cochleae identified with ANSD that lead to a CI, we performed intraoperative round window electrocochleography (ECochG) to tone bursts in children (n = 167) and adults (n = 163). Magnitudes of the responses to tones of different frequencies were summed to measure the “total response” (ECochG-TR), a metric often dominated by hair cell activity, and auditory nerve activity was estimated visually from the compound action potential (CAP) and auditory nerve neurophonic (ANN) as a ranked “Nerve Score”. Subjects identified as ANSD (45 ears in children, 3 in adults) had higher values of ECochG-TR than adult and pediatric subjects also receiving CIs not identified as ANSD. However, nerve scores of the ANSD group were similar to the other cohorts, although dominated by the ANN to low frequencies more than in the non-ANSD groups. To high frequencies, the common morphology of ANSD cases was a large CM and summating potential, and small or absent CAP. Common morphologies in other groups were either only a CM, or a combination of CM and CAP. These results indicate that responses to high frequencies, derived primarily from hair cells, are the main source of the CM used to evaluate ANSD in the clinical setting. However, the clinical tests do not capture the wide range of neural activity seen to low frequency sounds
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