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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Expression of Aquaporins in Mouse Choroid Plexus and Ependymal Cells

Patyal, Pankaj 01 September 2015 (has links)
No description available.
122

In Vitro Investigation Of Cerebrospinal Fluid Dynamics In Chiari Malformation By 4D Phase Contrast MRI

THYAGARAJ, SURAJ 09 June 2016 (has links)
No description available.
123

The Involvement of Lyn and the SH2-domain-containing Inositol 5’-Phosphatase 1 (SHIP1) in the Negative Regulation of M-CSF-induced Cellular Signaling Events

Baran, Christopher Phillip 12 May 2003 (has links)
No description available.
124

Optimization of Calcium-Dependent Affinity Ligands for Protein Purification

Öst, Linnea January 2021 (has links)
With an expanding life-science sector and growing production of recombinant proteins, the need for efficient downstream processing is increasing. Certain proteins are sensitive to the harsh conditions often used in protein purification, such as low pH, which can result in aggregation and denaturation. ZCa is a domain derived from Protein A that can be used for calcium-dependent purification of antibodies without the need for acidic pH. Based on this domain, the CaRA library has been constructed, which targets other therapeutic proteins than human antibodies. Four of the proteins isolated from the CaRA library, namely CaRA_scFv_1, CaRA_scFv_2, CaRA_G-CSF_1 and CaRA_G-CSF_3, are presented here for the purification of single chain variable fragment and granulate colony stimulating factor. The four proteins were produced as monomers, trimers and hexamers in an attempt to increase the binding capacity and attached to a matrix for purification using site-specific coupling. The successful binders CaRA_scFv_1 and CaRA_scFv_2 showed high affinity for their target protein scFv and were able to selectively capture an increased number of molecules through multimerization. Calcium-dependent binding was demonstrated by elution at neutral pH using the calcium chelator citrate, thus concluding that these multimerized CaRA variants can be used to considerably increase the efficiency in scFv purification while providing excellent purity and significantly reducing the risk of aggregation.
125

Myeloid specific regulation of NF-kB and M-CSF signaling in HIV-1 and AML

Kogan, Michael January 2013 (has links)
The HIV protein, Vpr, is a multifunctional accessory protein critical for efficient viral infection of target CD4+ T cells and macrophages. Vpr is incorporated into virus particles and functions to transport the preintegration complex into the nucleus where the process of viral integration into the host genome is completed. This action is particularly important in macrophages, which as a result of their terminal differentiation and non-proliferative status, would be otherwise more refractory to HIV infection. Vpr has several other critical functions including activation of HIV-1 LTR transcription, cell-cycle arrest due to DCAF-1 binding, and both direct and indirect contributions to T-cell dysfunction. The interactions of Vpr with molecular pathways in the context of macrophages, on the other hand, support accumulation of a persistent reservoir of HIV infection in cells of the myeloid lineage. The role of Vpr in the virus life cycle, as well as its effects on immune cells, appears to play an important role in the immune pathogenesis of AIDS and the development of HIV induced end-organ disease. In view of the pivotal functions of Vpr in virus infection, replication, and persistence of infection, this protein represents an attractive target for therapeutic intervention. Numerous studies have reported that Vpr alters NF-kappa B signaling in various cells, however, the findings have so far been largely conflicting with reports both stimulatory and inhibitory effects of Vpr. Our aim was to investigate the role of Vpr signaling in myeloid cells and address discrepancies that have been reported in the field. Our results show that Vpr expressed intracellularly is inhibitory to NF-kappa B, while extracelluar Vpr may have some stimulatory effects. Consistent with this notion, we report that Vpr has inhibitory effects that are specific to the TNF-alpha pathway, but not the LPS pathway, suggesting that multiple targets of Vpr may exist for NF-kappa B regulation. Further, we identify VprBP as one possible cellular component of Vpr's regulation of I-kappa B-alpha in response to TNF-alpha stimulation. We did not identify such a role for HSP27, which instead seems to inhibit Vpr functions. Finally, our findings suggest that NF-kappa B regulation by Vpr is further changed by the presence of other HIV-1 components within the cells, as U1 cells lacking Vpr were unexpectedly less responsive to TNF-alpha than those cells that had normal Vpr expression levels. This data suggests that Vpr may serve an important role in vivo by selectively inhibiting immune activation while stimulating NF-kappa B mediated viral production in HIV-1 infected T-cells and myeloid cells. M-CSF is a cytokine that promotes monocyte differentiation and survival. When over-expressed, M-CSF contributes to pathology in a wide variety of diseases including osteoporosis, obesity, certain human cancers, and in HIV-1 infection, particularly with respect to monocyte/macrophage infection and the development of HIV-1. In this study, our aim is to expand on the current knowledge of M-CSF regulation by NF-kappa B, a prominent transcription factor during inflammation and HIV-1 infection. Our results suggest that TNF-alpha promotes M-CSF secretion in macrophages and activates the -1310/+48 bp M-CSF promoter in Mono-Mac 1 cells. Inhibitors of the NF-kappa B pathway, diminish this response. We identified four putative NF-kappa B and four C/EBP-beta binding sites within the M-CSF promoter. Our findings using M-CSF promoter constructs mutated at individual NF-kappa B locations suggest these sites are redundant with respect to M-CSF promoter regulation. TNF-alpha treatment promoted NF-kappa B p65 binding to the M-CSF promoter in PMA treated U937 cells chronically infected with HIV-1 (U1 cells), but not in PMA treated uninfected U937 cells, suggesting that the presence of HIV-1 increases the NF-kappa B response. In conclusion, our findings demonstrate that NF-kappa B induces M-CSF expression on a promoter level via multiple functional NF-kappa B binding sites and that this pathway is likely relevant in HIV-1 infection of macrophages. The oncogenic potential of M-CSF receptor has been has been suggested over thirty years ago, however, few current studies have focused on the role of the receptor in AML. In a clinical trial for AML, Sunitinib was found to hold some efficacy for treating the disease. The authors hypothesized that the primary therapeutic target of Sunitinib in AML is FLT3 kinase. However, FLT3 inhibition alone has not been shown to recapitulate all the effects of Sunitinib in vitro and, furthermore, the drug is also known to have cross reactivity to other potential oncogenic receptors. In this study, we treated three myeloid cell lines, Mono-Mac 1, THP-1 and U937 with Sunitinib and a proprietary cFMS inhibitor from Johnson and Johnson to test the anti-cancer effect in of such treatment. We observed that only Mono-Mac 1 cells had diminished proliferation in vitro. Mono-Mac 1 cells had inhibited ERK as a result of cFMS inhibition and showed a dose dependent increase in cFMS expression with both Sunitinib and J&J cFMS-1 treatment. Our results suggest potential for cFMS as an important target of Sunitinib or other similar drugs AML, either independently or in combination with other targets. Alternatively, cFMS may be a marker for differentiation of AML and may be linked with responsiveness to certain therapeutics. In both cases, the future study of cFMS may produce more targeted therapeutic approaches and may be a suitable tool for the development of personalized medicine for AML. / Biomedical Neuroscience
126

Immunoteratological Studies of Diabetic Embryopathy Using Gene Expression Analysis

Punareewattana, Korawuth 23 April 2003 (has links)
Diabetic embryopathy is a major complication of pregnant women with type I diabetes. Immune defects in the pathogenesis of diabetic embryopathy have been suggested. We hypothesized that activated immune system can counteract diabetic effect and result in prevention of diabetic embryopathy. Diabetes was induced in pregnant ICR mice by streptozocin injection. Three different techniques of maternal immune stimulation, complete Freund's adjuvant (CFA), granulocyte-macrophage colony-stimulating factor (GM-CSF), or interferon-gamma (IFN-g), were used to stimulate the maternal immune system. Approximately 50% of fetuses from hyperglycemic (>27 mM/L) dams were malformed, with neural tube defects predominating. Maternal immune stimulation during the time of normoglycemia, i.e. prior to onset of hyperglycemia, was necessary for reducing teratogenic effects associated with hyperglycemia. The immune-stimulated diabetic mice then produced significantly lower numbers of malformed fetuses: CFA 20.9%, GM-CSF 23.3%, IFN-g 13.9%. A gene microarray was then used to examine a selected panel of placental and splenic genes. We hypothesized that a shared profile of placental or splenic gene expression changes may correlate to the reduced birth defect outcome induced by the different immune stimulation procedures. Diabetes did not cause significant changes in placenta or spleen gene expression profile. In placenta, CFA and GM-CSF changed placental gene expression relative to control or diabetes, but differentially affected such genes relative to each other; further, IFN-g did not affect gene expression relative to control or diabetes. Thus no common pattern of improved placental cytokine, cell-cycle, apoptotic, transcription factor, or other gene expression was identified in the immune-stimulated mice. In spleen, all 3 immune activators produced a common altered gene expression profile. The overall gene expression profile after all immune stimulation procedures suggested increased splenocyte activity and cytokine production. The cytokine GM-CSF, in particular, was up-regulated in splenic leukocytes. This cytokine has previously been associated with reduced cleft palate in urethane-exposed mice after immune stimulation, and with reduced limb malformations in cyclophosphamide-treated mice after intra-uterine administration. In contrast, the TGF-beta3 gene was down-regulated in immune-stimulated diabetic mice. This gene was up-regulated in urethane-exposed mice, an effect that may be associated with reduced cleft palate. Thus unlike urethane, TGF-beta3 gene expression did not show a relationship with reduced diabetes-induced birth defects. Taken together, these data prove our hypotheses and suggest that mechanistically diverse forms of immune activation result in protection against diabetes-related teratogenesis, but only if given prior to onset of hyperglycemia. Such immune stimulation in mice may act through systemic immune organs, i.e. spleen, over-riding adverse effects of diabetes on development. / Ph. D.
127

Critical success factors of the digital payment infrastructure for developing economies

Singh, N.K., Sahu, G.P., Rana, Nripendra P., Patil, P.P., Gupta, B. 25 September 2020 (has links)
Yes / This paper studies the Critical Success Factors’ (CSFs) for the adoption of Digital Payment System in India. There are few studies about the literature on CSFs for the adoption of the digital payment system in the Indian context. This study is an attempt to cover this gap. In this study, we reviewed the theories for adoption model at the individual level used in Information System (IS) and discussed four technology model including “Technology Acceptance Model” (TAM). Ten factors have been identified with extensive literature review and review of selected models namely; Perceived Ease of Use, Perceived functional benefits, Awareness, Availability of Resources, Government as a policy maker, Performance Expectancy, Social Influence, Price Value, Experience & Habit, and Risk-taking ability. An expert from academic industry has been taken as a reviewer or consultant of the selected variables. The CSFs may ensure that they are the predictors and the important factors for adoption of digital payments system in India. The study mainly uses the deductive approach to consider the primary and secondary sources of data. The analyses of these models take into account through Interpretive Structural Modeling (ISM) methodology and develop a model for effective adoption of Digital Payment System in India. The paper also makes future recommendations for further research studies.
128

Einfluss von Makrophagen auf autophagische Vorgänge in Schwann´schen Zellen unter den Bedingungen von Nervenläsion und genetisch bedingter Neuropathie / Influence of macrophages on Schwann cell autophagy under the conditions of nerve lesion and genetic neuropathy

Weiß, Eva Maria January 2024 (has links) (PDF)
Charcot-Marie-Tooth (CMT) Neuropathien stellen als häufigste erblich bedingte neurologische Erkrankungen eine Gruppe genetisch heterogener, chronisch progredienter peripherer Polyneuropathien dar. Die Lebensqualität der Patienten ist bei fehlender kurativer Therapieoption vor allem durch motorische und sensorische Defizite deutlich eingeschränkt. In verschiedenen Studien konnte die pathophysiologische Relevanz einer sekundären Entzündungsreaktion, insbesondere durch Makrophagen und Lymphozyten vermittelt, in Mausmodellen dreier CMT1 Subtypen (CMT1A, CMT1B, CMT1X) aufgezeigt werden. Auch in Folge einer Läsion peripherer Nerven ist eine akute Entzündungsreaktion von entscheidender Bedeutung, wobei sich bereits Gemeinsamkeiten zwischen der postläsionalen Waller´schen Degeneration (WD) und CMT1 Neuropathien identifizieren ließen. Während die aktive Beteiligung der Autophagie Schwann´scher Zellen (hier kurz SZ Autophagie genannt) an der Myelindegradation im Falle einer WD jedoch vielfach beschrieben wurde, ist Ähnliches in CMT1 Neuropathien bisher nur unzureichend untersucht. Da in einer Studie in Cx32def Mausmodellen der CMT1X Erkrankung auch nach Reduktion endoneuraler Makrophagen anhaltende Demyelinisierung beobachtet werden konnte, sollte das Vorkommen von SZ Autophagie sowie deren mögliche Beeinflussung durch Makrophagen in diesen Myelinmutanten untersucht werden. In der vorliegenden Arbeit wurden sowohl Wildtyp (Wt) Mäuse in ex vivo und in vivo Modellen einer WD als auch Cx32def Myelinmutanten zweier Altersstufen (4 und 12 Monate) mit einem niedermolekularen CSF1-Rezeptor-Inhibitor (CSF1RI) zur Reduktion endoneuraler Makrophagen behandelt, wobei sich vergleichende histochemische bzw. immunhistochemische Analysen peripherer Nerven behandelter und unbehandelter Tiere anschlossen. Im Rahmen der Etablierung immunhistochemischer Methodik zeigte sich hierbei unter den kontrollierten Bedingungen einer ex vivo Ischiasnervenkultur eine vermehrte Aktivierung der SZ Autophagie in behandelten Wt Mäusen. Auch 4 Monate alte behandelte Cx32def Tiere wiesen, verglichen mit unbehandelten Myelinmutanten bzw. Wt Mäusen derselben Altersstufe, eine vermehrte autophagische Aktivität in SZ auf. Diese scheint sich jedoch im weiteren Verlauf der Erkrankung zu reduzieren, da im Falle der 12 Monate alten Cx32def Modelltiere weniger autophagisch aktive SZ Profile bzw. kaum Unterschiede zwischen behandelten und unbehandelten Tieren beobachtet werden konnten. Die Ergebnisse lassen somit eine mögliche aktive Beteiligung von SZ Autophagie insbesondere in der Pathophysiologie der frühen Phase einer CMT1X Erkrankung sowie deren Beeinflussung durch endoneurale Makrophagen vermuten. Dies sollte vornehmlich in der Entwicklung von Therapiestrategien der CMT1X bedacht werden, da sich eine frühe Reduktion pathophysiologisch relevanter endoneuraler Makrophagen somit auch nachteilig auf die Myelinintegrität auswirken könnte. / Charcot-Marie-Tooth (CMT) neuropathies are the most common hereditary neurological diseases and represent a group of genetically heterogeneous, chronically progressive peripheral polyneuropathies. In the absence of curative treatment options, patients' quality of life is significantly impaired, primarily due to motor and sensory deficits. Various studies have demonstrated the pathophysiological relevance of a secondary inflammatory reaction, in particular mediated by macrophages and lymphocytes, in mouse models of three CMT1 subtypes (CMT1A, CMT1B, CMT1X). An acute inflammatory reaction is also of crucial importance following a lesion of peripheral nerves, whereby similarities between postlesional Wallerian degeneration (WD) and CMT1 neuropathies have already been identified. However, while the active involvement of Schwann cell autophagy (here referred to as SC autophagy) in myelin degradation in WD has been widely described, a similar involvement in CMT1 neuropathies has been insufficiently studied. Since in a study in Cx32def mouse models of CMT1X disease persistent demyelination could be observed even after reduction of endoneural macrophages, the occurrence of SC autophagy and its possible influence by macrophages in these myelin mutants should be investigated. In the present study, both wild-type (Wt) mice in ex vivo and in vivo models of WD and Cx32def myelin mutants of two ages (4 and 12 months) were treated with a small molecule CSF1 receptor inhibitor (CSF1RI) to reduce endoneural macrophages, followed by comparative histochemical and immunohistochemical analyses of peripheral nerves of treated and untreated animals, respectively. During the establishment of immunohistochemical methods, an increased activation of SC autophagy was shown in treated Wt mice under the controlled conditions of ex vivo sciatic nerve culture. Even 4-month-old treated Cx32def animals showed increased autophagic activity in SC compared to untreated myelin mutants or Wt mice of the same age. However, this appears to be reduced as the disease progresses, since in the case of the 12-month-old Cx32def model animals fewer autophagically active SC profiles or hardly any differences between treated and untreated animals could be observed. The results thus suggest a possible active involvement of SC autophagy, particularly in the pathophysiology of the early phase of CMT1X disease and its influence by endoneural macrophages. This should primarily be considered in the development of therapeutic strategies for CMT1X, as an early reduction of pathophysiologically relevant endoneural macrophages could therefore also have a detrimental effect on myelin integrity.
129

Modélisation pharmacocinétique/pharmacodynamique par une approche de population de l’effet du G-CSF chez des patients traités avec du carboplatine / Population pharmacokinetic/pharmacodynamic modelisation of G-CSF effect in carboplatin-treated patients

Pastor, Mélanie 19 July 2013 (has links)
Une des stratégies pour limiter les neutropénies induites par la chimiothérapie est l’utilisation de granulocyte-colony stimulating factor (G-CSF). Nous avons développé, par une approche de population, un nouveau modèle pharmacocinétique/pharmacodynamique capable de décrire la cinétique des neutrophiles des patients traités au carboplatine, qu’ils aient ou non reçu du G-CSF. Les simulations réalisées à partir de ce modèle ont montré que le G-CSF n’était pas bénéfique chez tous les patients et que la formulation à action longue semblerait plus efficace que les autres formulations. Nous avons également établi des règles de décision permettant d’une part de prédire le risque de neutropénie sévère, et d’autre part d’identifier précocement les patients pour lesquels le G-CSF peut avoir un effet bénéfique. / Granulocyte colony-stimulating factor (G-CSF) is often used in cancer patients receiving cytotoxic drugs to prevent or reduce high grade neutropenia. We developed a new population pharmacokinetic/pharmacodynamic model to describe neutrophil time-course in carboplatin-treated patients, whether or not they received G-CSF. Model simulations showed that G-CSF was not as beneficial as expected in some patients and that the onceper- cycle formulation was more efficient than other formulations. Model-based decision rules were also built to anticipate prolonged high grade neutropenia and early identify patients for whom G-CSF was beneficial.
130

Tau phosphorylation on threonine 217 as a potential biomarker for neurodegenerative diseases / Tau-fosforylering på treonin 217 som en potentiell biomarkör för neurodegenerativa sjukdomar

Omar Jama, Sukri January 2019 (has links)
Hyperfosforylering av biomarkörproteinet Tau förekommer i flera neurodegenerativa sjukdomar som kallas Taupathies. Proteinets huvudfunktion i människokroppen är att modulera flexibilitet och stabilitet för axonal-mikrotubulin. I Taupathies utlöser hyperfosforyleringen av Tau instabilitet och neurodegenerationen. I dagens läge kan hyperfosforylering av treonin 217 (P217) endast mätas i hjärnan. I den här studien undersöks hyperfosforyleringen av treonin 217 (P217). I syfte att se om nivåerna av P217 är mätbara i cerebrospinalvätska (CSV) och i blodet. Samt för att evaluera hur nivåer av P217 förändras i olika Taupathies, genom att testa hjärnprover från friska kontroller och olika Taupathies. Studien görs för att öka kunskapen om effekten av hyperfosforylering av treonin 217 i Taupathies och för att bidra med en ny provtagningsmetod för P217. Simoa HD-1 Analyzer var instrumentet som användes för analyserna av P217. Det är ett instrument som kan upptäcka onormala nivåer av biomarkörer genom kvantifiering, med hjälp av antikroppar och ett enzym. Enzymet kallas Streptavidin β-galaktosidas och omvandlar en befintlig P217-molekyl i proven till en fluorescerande produkt. Genom Simoa HD-1 Analyzer utvecklades en ultrasensitiv analys med antikropparna P217 och Tau 12, som kunde upptäcka mycket låga nivåer av P217 i hjärnan, CSF och i blod. Förändring av P217-nivåer hittades även i olika Taupathies. De Taupathies med de högsta nivåerna av P217 var Progressiv supranukleär pares, Corticobasal degeneration och Globular glial Taupathies. / Hyperphosphorylation of the biomarker protein Tau occurs in many neurodegenerative diseases called Taupathies. The proteins main function in the human body is to modulate flexibility and stability for axonal microtubules. In Taupathies the hyperphosphorylation of the Tau triggers instability and neurodegeneration. Nowdays hyperphoshorylation on threonine 217 (P217) can only be measured in the brain. In this study the hyperphoshorylation on the phosphorylation site of threonine 217 (P217) is examined. In aim to see if levels of P217 is measurable in cerebrospinal fluid (CSF) and in blood. As well to evaluate how P217 variate in different Taupathies, through the use of brain samples from healthy controls and different Taupathies. The study is made for the purpose of enhancing the pure knowledge about the effect of hyperphosphorylation on threonine 217 in Taupathies and to contribute with a new sampling method for P217. Simoa HD-1 Analyzer was the key instrument of the analyses of P217. It’s an instrument which can detect abnormal levels of biomarkers through quantification, with help of antibodies and an enzyme. The enzyme is called Streptavidin β-galactosidase and converts an existing P217 molecule in the samples to a fluoresce product. Through the use of Simoa HD-1 Analyzer an ultrasensitive assay with antibodies P217 and Tau 12 was developed which could detect very low levels of P217 in brain, CSF and in blood. Variation of P217 levels was also found in different Taupathies. The Taupathies with the highest levels of P217 was Progressive supranuclear palsy, Corticobasal Degeneration and Globular glial Taupathies.

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