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ROLE OF THE REGULATOR OF G PROTEIN SIGNALING 2 (RGS2) FOR NEURONAL AND SYSTEM FUNCTIONHan, Jing 04 April 2007 (has links)
No description available.
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Activation and regulation of TRP channelsXiao, Rui 16 September 2008 (has links)
No description available.
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Institutional Adaptation and Public Policy Practices of Military Transfer CreditBuechel, Kathryn Jean 10 February 2020 (has links)
Veterans who served our country, return with a wealth of experience that transfer into military credit for prior service. These transfer credits in institutions of higher education apply towards education degree attainment. With colleges and universities implementing individual policies for acceptance of credits, veterans experience a loss of credits leading to a duplication of required classes to achieve degrees. To understand inconsistent practices, both federal and institutions of higher education polices are examined. Framed by institutionalization theory, this research sheds light on the public policy process and administration of credit at the organization over time. The study provides findings for how the largest public college and higher education institution in the state of California awards academic credit for military education. Evidence suggests that public higher education institutions adapt based on effective leaders who define and defend the organization's institutional values and mission.
This study provides findings on institutional adaptations to create policies and practices that public administrators use to apply transfer military credit into postsecondary academic credit. The focus is on postsecondary credit transferred, or articulated, by entering military first-year students using the GI Bill. The study asks how have major institutions of higher education formalized institutional policies and practices on awarding academic credit for military education? / Doctor of Philosophy / This study provides findings on institutional adaptations to create policies and practices that public administrators use to apply transfer military credit into postsecondary academic credit. The focus is on postsecondary credit transferred, or articulated, by entering military first-year students using the GI Bill. The study asks how have major institutions of higher education formalized institutional policies and practices on awarding academic credit for military education?
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Does the MK2-dependent production of TNFα regulate mGluR-dependent synaptic plasticity?Hogg, Ellen L., Muller, Jurgen, Corrêa, Sonia A.L. 07 January 2016 (has links)
Yes / The molecular mechanisms and signalling cascades that trigger the induction of group I metabotropic glutamate receptor (GI-mGluR)-dependent long-term depression (LTD) have been the subject of intensive investigation for nearly two decades. The generation of genetically modified animals has played a crucial role in elucidating the involvement of key molecules regulating the induction and maintenance of mGluR-LTD. In this review we will discuss the requirement of the newly discovered MAPKAPK-2 (MK2) and MAPKAPK-3 (MK3) signalling cascade in regulating GI-mGluR-LTD. Recently, it has been shown that the absence of MK2 impaired the induction of GI-mGluR-dependent LTD, an effect that is caused by reduced internalization of AMPA receptors (AMPAR). As the MK2 cascade directly regulates tumour necrosis factor alpha (TNFα) production, this review will examine the evidence that the release of TNFα acts to regulate glutamate receptor expression and therefore may play a functional role in the impairment of GI-mGluRdependent LTD and the cognitive deficits observed in MK2/3 double knockout animals. The strong links of increased TNFα production in both aging and neurodegenerative disease could implicate the action of MK2 in these processes. / This work was supported by the BBSRC-BB/H018344/1 to S.A.L.C.
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Studies of viral and cellular proteins involved in herpes simplex virus type-1 egressAhmed, Md Firoz January 2019 (has links)
The egress pathway of herpes simplex virus-1 (HSV-1) is a complicated process mediated by co-ordinated activity of several virus glycoproteins. The virions are first assembled and enveloped at trans-Golgi-network (TGN) or endosome membranes and then travel through a guided pathway that is directed towards the cell adherent points for secretion. Once secreted the vast majority of virions remain associated with the extracellular membrane of cells and very few free virions are released into the culture medium (< 1%). The mechanisms that mediate both the targeted secretion of newly assembled virions at cell contact points and post-secretion attachment of virions with the extracellular surface of cells are poorly understood, and were the topics of this research. In this thesis, an HSV-1 passage mutant of increased virion secretion phenotype had been studied. Genome sequencing of the mutant virus identified mutations in three viral envelope proteins. Study of recombinant viruses that were constructed based on those three mutations revealed that a single amino acid change in glycoprotein I (gI) of glycine to arginine at residue 39 is responsible for the increased release of virus. The result suggests the principal effect of this mutation is to modify the secretory pathway used by virions during their release from infected cells. Data also suggests a role of gC in the attachment of virions to the extracellular surface of cells after egress. In the context of HSV-1 envelopment and egress glycoprotein E (gE), which forms a heterodimeric complex with gI (gE/gI), is known to be important. The gE/gI complex has been shown to interact with many tegument proteins and have a redundant role in secondary envelopment. The gE/gI complex has been also proposed to colocalise with various cellular components and sort the nascent virions to cell contact points. However, there is little understanding of the cellular proteins that gE/gI interact with, or the mechanisms that mediate targeted secretion of virions. This research has identified a novel interactome of gE/gI by mass-spectrometric analysis utilising stable isotope labelling with amino acids in cell culture (SILAC) medium. Among the cellular interactome obtained, Nipsnap1 was validated by co-precipitation assays from both infected and transfected cells, and furthermore using cell free systems, suggesting gE and Nipsnap1 directly interact. Nipsnap1 and its homologue Nipsnap2 have been proposed to contribute in vesicle transport and membrane fusion in cells. Using CRISPR-Cas9 technology these proteins were knocked out in a keratinocyte cell line (HaCaT) to investigate their role in HSV-1 egress. However, little or no effect on HSV-1 egress could be observed upon loss of either or both of these proteins suggesting the biological significance of gE-Nipsnap1 interaction may not be directly linked to any egress function of gE/gI. Two further interesting 'hits' from the gE/gI interactome were interferon-induced transmembrane protein type-2 (IFITM2), a virus restriction factor, and Myoferlin that has a putative role in endocytic vesicle recycling. This study could validate gE-Myoferlin interaction and co-localisation in infected or transfected cells however, functional significance of this interaction remains to be determined. Overall, the research of this thesis has provided a better understanding of the role of the gE/gI complex in HSV-1 egress and investigated the role of some interesting cellular proteins in the context of virion egress.
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Selenabhängige Glutathionperoxidasen als Mediatoren und Ziele der intrazellulären Redoxregulation : Identifizierung der GI-GPx als Ziel für Nrf2 und der PHGPx ... / Selenium-dependent glutathione peroxidases as mediators and targets of intracellular redox regulationBanning, Antje January 2005 (has links)
Das 1817 erstmals schriftlich erwähnte Selen galt lange Zeit nur als toxisch und sogar als procancerogen, bis es 1957 von Schwarz und Foltz als essentielles Spurenelement erkannt wurde, dessen biologische Funktionen in Säugern durch Selenoproteine vermittelt werden. Die Familie der Glutathionperoxidasen nimmt hierbei eine wichtige Stellung ein. Für diese sind konkrete Funktionen und die dazugehörigen molekularen Mechanismen, welche über die von ihnen katalysierte Hydroperoxidreduktion und damit verbundene antioxidative Kapazität hinausgehen, bislang nur unzureichend beschrieben worden. <br><br>
Die Funktion der gastrointestinalen Glutathionperoxidase (GI-GPx) wird als Barriere gegen eine Hydroperoxidabsorption im Gastrointestinaltrakt definiert. Neuen Erkenntnissen zufolge wird die GI-GPx aber auch in verschiedenen Tumoren verstärkt exprimiert, was weitere, bis dato unbekannte, Funktionen dieses Enzymes wahrscheinlich macht.<br>
Um mögliche neue Funktionen der GI-GPx, vor allem während der Cancerogenese, abzuleiten, wurde hier die transkriptionale Regulation der GI-GPx detaillierter untersucht. Die Sequenzanalyse des humanen GI-GPx-Promotors ergab das Vorhandensein von zwei möglichen "antioxidant response elements" (ARE), bei welchen es sich um Erkennungssequenzen des Transkriptionsfaktors Nrf2 handelt. Die meisten der bekannten Nrf2-Zielgene gehören in die Gruppe der Phase-II-Enzyme und verfügen über antioxidative und/oder detoxifizierende Eigenschaften. Sowohl auf Promotorebene als auch auf mRNA- und Proteinebene konnte die Expression der GI-GPx durch typische, in der Nahrung enthaltene, Nrf2-Aktivatoren wie z.B. Sulforaphan oder Curcumin induziert werden. Eine direkte Beteiligung von Nrf2 wurde durch Cotransfektion von Nrf2 selbst bzw. von Keap1, das Nrf2 im Cytoplasma festhält, demonstriert. Somit konnte die GI-GPx eindeutig als Nrf2-Zielgen identifiziert werden. Ob sich die GI-GPx in die Gruppe der antiinflammatorischen und anticancerogenen Phase-II-Enzyme einordnen lässt, bleibt noch zu untersuchen. <br><br>
Die Phospholipidhydroperoxid Glutathionperoxidase (PHGPx) nimmt aufgrund ihres breiten Substratspektrums, ihrer hohen Lipophilie und ihrer Fähigkeit, Thiole zu modifizieren, eine Sonderstellung innerhalb der Familie der Glutathionperoxidasen ein. Mit Hilfe eines PHGPx-überexprimierenden Zellmodells wurden deshalb Beeinflussungen des zellulären Redoxstatus und daraus resultierende Veränderungen in der Aktivität redoxsensitiver Transkriptionsfaktorsysteme und in der Expression atheroskleroserelevanter Adhäsionsmoleküle untersucht. Als Transkriptionsfaktoren wurden NF-kB und Nrf2 ausgewählt. Die Bindung von NF-kB an sein entsprechendes responsives Element in der DNA erfordert das Vorhandensein freier Thiole, wohingegen Nrf2 durch Thiolmodifikation von Keap1 freigesetzt wird und in den Kern transloziert. Eine erhöhte Aktivität der PHGPx resultierte in einer Erhöhung des Verhältnisses von GSH zu GSSG, andererseits aber in einer verminderten Markierbarkeit freier Proteinthiole. PHGPx-Überexpression reduzierte die IL-1-induzierte NF-kB-Aktivität, die sich in einer verminderten NF-kB-DNA-Bindefähigkeit und Transaktivierungsaktivität ausdrückte. Auch war die Proliferationsrate der Zellen vermindert. Die Expression des NF-kB-regulierten vaskulären Zelladhäsionsmoleküls, VCAM-1, war ebenfalls deutlich verringert. Umgekehrt war in PHGPx-überexprimierenden Zellen eine erhöhte Nrf2-Aktivität und Expression der Nrf2-abhängigen Hämoxygenase-1 zu verzeichnen. Letzte kann für die meisten der beobachteten Effekte verantwortlich gemacht werden.<br><br>
Die hier dargestellten Ergebnisse verdeutlichen, dass eine Modifizierung von Proteinthiolen als wichtige Determinante für die Regulation der Expression und Funktion von Glutathionperoxidasen angesehen werden kann. Entgegen früheren Vermutungen, welche oxidative Vorgänge generell mit pathologischen Veränderungen assoziierten, scheint ein moderater oxidativer Stress, bedingt durch eine transiente Thiolmodifikation, durchaus günstige Auswirkungen zu haben, da, wie hier dargelegt, verschiedene, miteinander interagierende, cytoprotektive Mechanismen ausgelöst werden. Hieran wird deutlich, dass sich "antioxidative Wirkung" oder "oxidativer Stress" keineswegs nur auf "gute" oder "schlechte" Vorgänge beschränken lassen, sondern im Zusammenhang mit den beeinflussten (patho)physiologischen Prozessen und dem Ausmaß der "Störung" des physiologischen Redoxgleichgewichtes betrachtet werden müssen. / Selenium was discovered in 1817 by the Swedish chemist Berzelius and was for a long time considered as being toxic and even procarcinogenic. In 1957, however, Schwarz and Foltz realized that selenium is an essential trace element which elicits its biological functions in mammals as a structural component of selenoproteins among which the family of glutathione peroxidases plays a dominant role. Glutathione peroxidases reduce hydroperoxides to the corresponding alcohols and contribute to the antioxidative capacity of a cell. However, other functions of glutathione peroxidases and the according molecular mechanisms have hardly been described.>br><br>
The gastrointestinal glutathione peroxidase (GI-GPx) is believed to build a barrier against the absorption of foodborne hydroperoxides. In addition, GI-GPx expression is increased in different tumors. This indicates further, still unknown, functions of this enzyme.<br>
In order to elucidate new possible functions of GI-GPx, especially during carcinogenesis, the transcriptional regulation of GI-GPx was analyzed in more detail. An analysis of the GI-GPx promoter sequence revealed the presence of two putative "antioxidant response elements" (ARE) which are recognition sites for the transcription factor Nrf2. Most of the known Nrf2 target genes either belong to the group of phase-II detoxification enzymes or possess antioxidative and/or detoxifying properties. On promoter level as well as on mRNA- and protein level the expression of GI-GPx was induced by typical Nrf2-activating compounds such as sulforaphane or curcumin that are contained in the diet. A direct involvement of Nrf2 was demonstrated by cotransfection of Nrf2 itself or by cotransfection of Keap1 which retains Nrf2 in the cytosol. Thus, the GI-GPx gene was unequivocally identified as a new target for Nrf2. Whether GI-GPx also belongs in the category of antiinflammatory and anticarcinogenic enzymes remains to be elucidated.<br><br>
The phospholipid hydroperoxide glutathione peroxidase (PHGPx) is exceptional among the glutathione peroxidases because of its broad range of substrates, its high lipophilicity, and its ability to modify protein thiols. With PHGPx-overexpressing cells, the influence of PHGPx on the cellular redox state and on resulting changes in the activity of redox-sensitive transcription factors and on the expression of proatherogenic adhesion molecules was analyzed. For this, the redox-sensitive transcription factors NF-kB and Nrf2 were chosen. NF-kB requires free thiols for being able to bind to its responsive element within the DNA, whereas Nrf2 is released from Keap1 and translocates to the nucleus upon a modification of protein thiols. PHGPx-overexpression resulted in an increase in the ratio of GSH to GSSG, in a reduced amount of intracellular protein thiols, and in a diminished proliferation rate. Furthermore, PHGPx-overexpressing cells displayed a reduced IL-1-dependent NF-kB activity as was assessed by a reduced NF-kB DNA-binding ability and activity of a NF-kB-driven reporter gene. In addition, the expression of the NF-kB-dependent vascular cell adhesion molecule (VCAM-1) was also inhibited by overexpression of PHGPx. On the other hand, PHGPx-overexpressing cells displayed an increased activity of Nrf2 that was accompanied by an increased expression of the Nrf2-dependent heme oxygenase-1. Heme oxygenase-1 most likely is responsible for most of the aforementioned effects.<br><br>
The data presented here show that a modification of protein thiols can be regarded as an important determinant for the regulation and for the functions of glutathione peroxidases. In contrast to the previous assumption that oxidative processes are always linked to pathologic changes, a moderate oxidative stress seems to have beneficial effects, because it triggers different cytoprotective mechanisms. It can be concluded that the terms "antioxidative effect" or "oxidative stress" cannot simply be restricted to "good" or "bad" processes, but need to be seen in context with the modulated (patho)physiological processes and the degree of "disturbance" of the physiologic redox balance.
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Development of a freehand three-dimensional radial endoscopic ultrasonography systemInglis, Scott January 2009 (has links)
Oesophageal cancer is an aggressive malignancy with an overall five-year survival of 5-10% and two-thirds of patients have irresectable disease at diagnosis. Accurate staging of oesophageal cancer is important as survival closely correlates with the stage of the tumour, nodal involvement and presence of metastases (TNM staging). Endoscopic ultrasonography (EUS) is currently the most reliable modality for providing accurate T and N staging. Depending on findings of the staging, various treatment options including endoscopic, oncological, and surgical treatments may be performed. It was theorised that the development of three-dimensional radial endoscopic ultrasonography would reduce the operator dependence of EUS and provide accurate dimensional and volume measurements to aid planning and monitoring of treatment. This thesis investigates the development of a three dimensional endoscopic ultrasound technique that can be used with the radial echoendoscopes. Various agar-based tissue mimicking material (TMM) recipes were characterised using a scanning acoustic macroscope to obtain the acoustic properties of attenuation, backscatter and speed of sound. Using these results, a number of endoscopic ultrasound phantoms were developed for the in-vitro investigation and evaluation of 3D-EUS techniques. To increase my understanding of EUS equipment, the imaging and acoustic properties of the EUS endoscopes were characterised using a pipe phantom and a hydrophone. The dual ‘single element’ mechanical and ‘multi-element’ electronic echoendoscopes were investigated. Measured imaging properties included dead space, low contrast penetration, and pipe length. The measured acoustic properties included transmitted beam plots, active working frequency and peak pressures. Three-dimensional ultrasound techniques were developed for specific application to EUS. This included the study of positional monitoring systems, reconstruction algorithms and measurement techniques. A 3D-EUS system was developed using a Microscribe positional arm and frame grabber card, to acquire the 3D dataset. A Matlab 3D-EUS toolbox was written to reconstruct and analyse the volumes. The 3D-EUS systems were evaluated on the EUS phantom and in clinical cases. The usefulness of the 3D-EUS systems was evaluated in a cohort of patients, who were routinely investigated by conventional EUS for a variety of upper gastrointestinal pathology. 3D-EUS accurately staged early tumours and provided the necessary anatomical information to facilitate treatment. With regards to more advanced tumours, 3D-EUS was more accurate than EUS in T and N staging. 3D-EUS gave useful anatomical details in a variety of benign conditions such as varicies and GISTs.
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Effects of HIV-1 Tat on the enteric nervousNgwainmbi, Joy 01 January 2015 (has links)
More than 1.2 million people are estimated to be currently living with the human immunodeficiency virus (HIV) in the United States of America. The gastrointestinal (GI) tract is both a major target and an important component of HIV pathogenesis. The GI processes that are dysregulated during HIV infection are controlled by the enteric nervous system (ENS). Indeed, both clinical and experimental studies have implicated the ENS in HIV and simian immunodeficiency virus (SIV) pathogenesis. In addition to direct viral effects, the HIV virus also indirectly affects the GI tract via cellular and/or viral toxins released by infected cells. Trans-activator of transcription (Tat) is a viral toxin that plays an important role in replication of the HIV virus. While, the HIV virus does not directly infect neurons, Tat has been shown to modulate neuronal function. HIV infection in the gut is accompanied by: translocation of bacteria and bacterial products from the gut lumen to peripheral blood, immune activation and inflammation. Lipopolysaccharide (LPS) is a major bacterial product that is used to determine the rate of bacterial translocation and to drive inflammation. Despite reports of enteric ganglionitis in SIV infected monkeys and autonomic denervation in the jejunum of HIV patients, little is known of the mechanism underlying enteric neuropathogenesis in HIV and the role of the ENS in HIV pathogenesis. In the present study, we assessed the effects of Tat on enteric neuronal excitability and how Tat and LPS interact in the ENS to bring about inflammation and GI motility problems observed in HIV patients. We show that Tat significantly increased enteric neuronal excitability by modulating sodium channels expressed on enteric neurons. Tat sensitized ENS cells to LPS-mediated increase in pro-inflammatory cytokines via a TLR4-mediated pathway involving MyD88. Mice expressing the tat transgene (Tat+) had faster GI transit rates and significantly higher frequencies of diameter changes in the proximal ileum than controls (Tat-). Tat+ mice were also more sensitive to LPS-mediated decreases in colonic transit rate. This study highlights the role of viral and bacterial proteins in HIV pathogenesis in the gastrointestinal tract and also demonstrates a critical role of the ENS in HIV pathogenesis.
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Vliv morfinu na distribuci signálních molekul opioidního systému v lipidových raftech izolovaných z myokardu potkana / The effect of morphine on the distribution of signaling molecules of the opioid system in lipid rafts prepared from rat heartLadislav, Marek January 2013 (has links)
Morphine is an opioid agonist, which can exert cardioprotective effects under certain conditions. Lipid rafts are considered important platforms for membrane organization of signaling proteins and, therefore, these structures could play a role in the effects of morphine, which acts through the opioid receptors. The aim of this thesis was to investigate the distribution of the main components of the opioid receptor and Gi/o-mediated signaling pathway in lipid rafts isolated from rat myocardium, which was affected by various doses of morphine. Because we used different isolation techniques with different solubilization agents (Triton X-100, CHAPS, cholate and sodium carbonate) for preparation of lipid rafts, it was of interest to characterize more closely these preparations. Another aim of this study was to investigate how different methods of isolating these structures affect activity of the key target enzyme of the opioid signaling pathway, i.e. adenylyl cyclase. The presence of signaling molecules of the Gi/o/AC pathway of the opioid system in membrane rafts was confirmed and the distribution of selected proteins was dependent on the type of extractant. We also observed the effect of morphine on the localization of proteins in lipid rafts. Different extractants provided different degree of...
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The Post-9/11 GI Bill and its Role in For-Profit University EnrollmentPaul, Irma 01 January 2019 (has links)
There is limited research on the Post-9/11 Veterans Educational Assistance Act of 2008, known as the 9/11 GI Bill, which provides educational benefits to veterans who have served in the United States military on active duty for 90 days. While outcomes for public and nonprofit universities are well known, less is known about whether proprietary universities are successful in recruitment and enrollment of veterans under the 9/11 GI Bill. The purpose of this phenomenological study was to examine the experiences that veterans who were Post 9/11 Bill beneficiaries had with recruitment strategies and institutional public policy practices from for-profit institutions. Ten veterans who participated in this study received Post-9/11 GI Bill educational benefits and enrolled in a for-profit institution based in Florida. Data was collected using the transcripts of the responses from the face-to-face interviews. These data were inductively coded and analyzed using a modified Van Kaam analysis procedure. The findings indicated that for-profit institutions used excessive recruitment strategies and aggressive targeting to attract veterans who received Post-9/11 GI Bill educational benefits. The findings also suggested that for-profit universities appear to need institutional policy changes and programs to assist veterans in transitioning from academic to civilian life. Recommendations to Veterans' Affairs Offices, legislators, and leaders of proprietary institutions that support positive social change include mandatory reporting of federal funds, development of civilian transition programs, and adopting of key collaborations within departments. These recommendations may promote successful educational outcomes and sustainable employment for veterans.
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