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The role of βc subunit phosphorylation in the functioning of the GM-CSF/IL-3/IL-5 receptors.Winnall, Wendy January 2008 (has links)
The cytokines GM-CSF, IL-3 and IL-5 are central regulators of haemopoietic cell functions and are pivotal in the regulation of haemopoiesis and inflammatory responses of myeloid cells. In particular, these cytokines have been shown to perform essential functions in host defence against foreign pathogens through their ability to regulate innate immune responses in myeloid cells. As key regulators of such important processes, these cytokines play an important role in human inflammatory pathologies such as rheumatoid arthritis, asthma, multiple sclerosis and psoriasis as well as a number of leukemias such as JML and CMML. GM-CSF, IL-3 and IL-5 signal through receptors containing α subunits specific to each cytokine and a common β subunit (βc). Cytokine stimulation leads to tyrosine phosphorylation of the βc and promotes specific responses such as proliferation, survival and activation of haemopoietic cells. Mouse knockout studies identified a key function of these cytokines in the activation of effector functions of myeloid cells, including production of reactive oxygen species (ROS) and phagocytosis. These earlier studies provide a link between cytokine signalling and inflammation, but the molecular mechanisms by which βc activation regulates effector cell functions, and the receptor motifs involved, are unknown. The aim of this thesis was to address two broad questions with regard to βc signalling: (1) Does βc regulate specific cellular responses by phosphotyrosine-independent mechanisms? (2) What are the molecular mechanisms by which βc initiates signalling to promote specific biological responses such as activation of effector cell functions? To address the first question, we have focussed on Serine 585, a potential 14-3-3 binding site which lies in the cytoplasmic potion of huβc. Out results show that the mutation huβc S585G disrupted the interaction of 14-3-3ζ with βc, whilst not affecting receptor tyrosine phosphorylation. Both mouse and human βc were shown to interact with 14-3-3 proteins, indicating that this interaction is conserved between these species. Significantly, a huβc S585G mutant was unable to promote haemopoietic cell survival in response to IL-3. These results identify a new mechanism by which cytokine receptors are able to couple to downstream signalling pathways that regulate cell survival. An approach was developed and optimised to analyse specific GM-CSF-mediated responses in monocytes/macrophages expressing wildtype or mutant huβc, (including huβc S585G that was defective in regulating survival). Bone marrow-derived muβc -/-;muβIL-3 -/- monocytes/macrophages were retrovirally transduced with constructs expressing wildtype or mutant huβc, along with huGMRα, then purified by FACS. Two assays were established to measure effector functions in the transduced monocyte/macrophages; (1) a flow cytometry assay for ROS production, and (2) an assay for phagocytosis. The capacity for GM-CSF to prime (i.e. enhance effector functions) ROS production and phagocytosis was investigated in huGMRα-transduced monocytes/macrophages. Our results have identified two key residues in the cytoplasmic domain of βc subunit: Tyrosine 577 (required for huβc interaction with the adaptor protein Shc) and serine 585 (required for 14-3-3 association), that are essential for the ability of GM-CSF to regulate key effector functions in monocytes/macrophages. These novel findings are significant in that they establish a molecular link between the GM-CSF/IL-3/IL-5 receptor and the regulation of both haemopoietic cell survival and inflammatory responses, and therefore have important implications in our understanding of inflammatory diseases such as rheumatoid arthritis and asthma. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1317007 / Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 2008
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Individually Tailored Toxicity-based Chemotherapy : Studies on Patients with Primary and Metastatic Breast CancerLindman, Henrik January 2003 (has links)
<p>Standard dosing of chemotherapy based on body surface area (BSA) results in large individual differences in toxicity due to a large inter-patient variability in pharmacokinetics (PK) and pharmacodynamics (PD). This results in under-dosing in certain patients with a potentially weaker antitumoral effect.</p><p>Three clinical studies of individually tailored dosing of chemotherapy, based on haematological toxicity were conducted. In the first study, 26 women with metastatic breast cancer were treated with tailored and dose-escalated 5-fluorouracil, epirubicin and cyclophosphamide, supported by G-CSF (dFEC). In the second study 525 patients with high-risk primary breast cancer were randomised between dFEC and high-dose chemotherapy with autologous bone-marrow transplantation. The feasibility of a FEC regimen with doubled cyclophosphamide dose to mobilise peripheral stem cells was investigated. In the third study, 44 metastatic patients were treated with tailored epirubicin and docetaxel (ET). PK and PD were also investigated in these patients. The potential effects of G-CSF on MRI tumour evaluation were studied in 18 patients with skeletal metastases.</p><p>Toxicity-based dosing entailed an evenly distributed two- to three-fold range of tolerated doses in all three studies. Efficacy and toxicity were not correlated to tolerated dose-levels. Tailored dFEC resulted in a response rate of 81% and the same regimen resulted in fewer breast cancer relapses compared with standard FEC followed by high-dose therapy. Toxicity was manageable except for an increased rate of secondary leukaemia. The modified FEC could safely mobilise sufficient numbers of stem-cells. Tailored ET resulted in a response rate of 63%. The inter-individual variability in drug clearance was larger than the inter-occasion variability and a semi-physiological model of PK and PD could predict leukocyte nadir and duration. An increased diffuse MR signal in the long TE IR-TSE sequence was observed in normal bone-marrow during G-CSF treatment; this could be mistaken as disseminated metastatic disease and could obscure focal metastases.</p><p>In conclusion, the concept of individually tailored toxicity-based dosage of chemotherapy was equally feasible in primary and metastatic breast cancer, in two different chemotherapy regimens and in treatment with or without G-CSF support and may provide a pragmatic way of overcoming the shortcomings of standard BSA-based dosing.</p>
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Electrifying the Molecules of Life : Peptide and Protein Analysis by Capillary Electrophoresis Coupled to Electrospray Ionization Mass SpectrometryWetterhall, Magnus January 2004 (has links)
<p>This thesis describes the current status and novel aspects of the analysis of the molecules of life, i.e. peptides and proteins, using capillary electrophoresis (CE) coupled to mass spectrometry (MS) via (sheathless) electrospray ionization (ESI). Early reports of sheathless CE-ESI-MS were plagued by limited lifetimes of the electrospray emitter. In this thesis, two new approaches, the Black Dust and the Black Jack methods, utilizing polymer-embedded graphite instead of noble metals are presented. These emitters have shown improved long-term stability and proven excellent for sheathless electrospray operation. Failure of an emitter is often caused by electrochemical reactions occurring at the emitter-liquid interface. The electrochemical properties of the graphite coated emitters were therefore evaluated by classical electrochemical methods, such as cyclic voltammetry and chronoamperometry. The graphite coated emitters showed excellent electrochemical stability and properties compared to noble metal and polymer configurations.</p><p>Analyte-wall interactions have long been known to cause problems in the CE analysis of biomolecules. This can be circumvented by internal modification of the capillary walls. Additionally, it is of outermost importance to have a stable and sufficiently high electroosmotic flow (EOF) to sustain the electrospray, when using a sheathless approach. New monomer and polymer coatings are presented for rapid and high-efficient CE-ESI-MS separations of peptides and proteins.</p><p>Furthermore, the use of CE-ESI coupled to Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) shows great potential for rapid proteomic probing of human cerebrospinal fluid. The results are comparable with more established techniques, such as liquid chromatography and two-dimensional gel electrophoresis coupled to MS. However, the CE-ESI-FTICRMS analysis has significantly lower sample consumption and faster analysis time compared to the other techniques. The applications and use of CE-ESI-MS is expected to have a bright future with continued growth as current trends of multidimensional hyphenation and microfabricated devices are further developed and explored.</p>
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Electrifying the Molecules of Life : Peptide and Protein Analysis by Capillary Electrophoresis Coupled to Electrospray Ionization Mass SpectrometryWetterhall, Magnus January 2004 (has links)
This thesis describes the current status and novel aspects of the analysis of the molecules of life, i.e. peptides and proteins, using capillary electrophoresis (CE) coupled to mass spectrometry (MS) via (sheathless) electrospray ionization (ESI). Early reports of sheathless CE-ESI-MS were plagued by limited lifetimes of the electrospray emitter. In this thesis, two new approaches, the Black Dust and the Black Jack methods, utilizing polymer-embedded graphite instead of noble metals are presented. These emitters have shown improved long-term stability and proven excellent for sheathless electrospray operation. Failure of an emitter is often caused by electrochemical reactions occurring at the emitter-liquid interface. The electrochemical properties of the graphite coated emitters were therefore evaluated by classical electrochemical methods, such as cyclic voltammetry and chronoamperometry. The graphite coated emitters showed excellent electrochemical stability and properties compared to noble metal and polymer configurations. Analyte-wall interactions have long been known to cause problems in the CE analysis of biomolecules. This can be circumvented by internal modification of the capillary walls. Additionally, it is of outermost importance to have a stable and sufficiently high electroosmotic flow (EOF) to sustain the electrospray, when using a sheathless approach. New monomer and polymer coatings are presented for rapid and high-efficient CE-ESI-MS separations of peptides and proteins. Furthermore, the use of CE-ESI coupled to Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) shows great potential for rapid proteomic probing of human cerebrospinal fluid. The results are comparable with more established techniques, such as liquid chromatography and two-dimensional gel electrophoresis coupled to MS. However, the CE-ESI-FTICRMS analysis has significantly lower sample consumption and faster analysis time compared to the other techniques. The applications and use of CE-ESI-MS is expected to have a bright future with continued growth as current trends of multidimensional hyphenation and microfabricated devices are further developed and explored.
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Individually Tailored Toxicity-based Chemotherapy : Studies on Patients with Primary and Metastatic Breast CancerLindman, Henrik January 2003 (has links)
Standard dosing of chemotherapy based on body surface area (BSA) results in large individual differences in toxicity due to a large inter-patient variability in pharmacokinetics (PK) and pharmacodynamics (PD). This results in under-dosing in certain patients with a potentially weaker antitumoral effect. Three clinical studies of individually tailored dosing of chemotherapy, based on haematological toxicity were conducted. In the first study, 26 women with metastatic breast cancer were treated with tailored and dose-escalated 5-fluorouracil, epirubicin and cyclophosphamide, supported by G-CSF (dFEC). In the second study 525 patients with high-risk primary breast cancer were randomised between dFEC and high-dose chemotherapy with autologous bone-marrow transplantation. The feasibility of a FEC regimen with doubled cyclophosphamide dose to mobilise peripheral stem cells was investigated. In the third study, 44 metastatic patients were treated with tailored epirubicin and docetaxel (ET). PK and PD were also investigated in these patients. The potential effects of G-CSF on MRI tumour evaluation were studied in 18 patients with skeletal metastases. Toxicity-based dosing entailed an evenly distributed two- to three-fold range of tolerated doses in all three studies. Efficacy and toxicity were not correlated to tolerated dose-levels. Tailored dFEC resulted in a response rate of 81% and the same regimen resulted in fewer breast cancer relapses compared with standard FEC followed by high-dose therapy. Toxicity was manageable except for an increased rate of secondary leukaemia. The modified FEC could safely mobilise sufficient numbers of stem-cells. Tailored ET resulted in a response rate of 63%. The inter-individual variability in drug clearance was larger than the inter-occasion variability and a semi-physiological model of PK and PD could predict leukocyte nadir and duration. An increased diffuse MR signal in the long TE IR-TSE sequence was observed in normal bone-marrow during G-CSF treatment; this could be mistaken as disseminated metastatic disease and could obscure focal metastases. In conclusion, the concept of individually tailored toxicity-based dosage of chemotherapy was equally feasible in primary and metastatic breast cancer, in two different chemotherapy regimens and in treatment with or without G-CSF support and may provide a pragmatic way of overcoming the shortcomings of standard BSA-based dosing.
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Metabolomics studies of ALS : a multivariate search for clues about a devastating diseaseWuolikainen, Anna January 2009 (has links)
Amyotrophic lateral sclerosis (ALS), also known as Charcot’s disease, motor neuron disease (MND) and Lou Gehrig’s disease, is a deadly, adult-onset neurodegenerative disorder characterized by progressive loss of upper and lower motor neurons, resulting in evolving paresis of the linked muscles. ALS is defined by classical features of the disease, but may present as a wide spectrum of phenotypes. About 10% of all ALS cases have been reported as familial, of which about 20% have been associated with mutations in the gene encoding for CuZn superoxide dismutase (SOD1). The remaining cases are regarded as sporadic. Research has advanced our understanding of the disease, but the cause is still unknown, no reliable diagnostic test exists, no cure has been found and the current therapies are unsatisfactory. Riluzole (Rilutek®) is the only registered drug for the treatment of ALS. The drug has shown only a modest effect in prolonging life and the mechanism of action of riluzole is not yet fully understood. ALS is diagnosed by excluding diseases with similar symptoms. At an early stage, there are numerous possible diseases that may present with similar symptoms, thereby making the diagnostic procedure cumbersome, extensive and time consuming with a significant risk of misdiagnosis. Biomarkers that can be developed into diagnostic test of ALS are therefore needed. The high number of unsuccessful attempts at finding a single diseasespecific marker, in combination with the complexity of the disease, indicates that a pattern of several markers is perhaps more likely to provide a diagnostic signature for ALS. Metabolomics, in combination with chemometrics, can be a useful tool with which to study human disease. Metabolomics can screen for small molecules in biofluids such as cerebrospinal fluid (CSF) and chemometrics can provide structure and tools in order to handle the types of data generated from metabolomics. In this thesis, ALS has been studied using a combination of metabolomics and chemometrics. Collection and storage of CSF in relation to metabolite stability have been extensively evaluated. Protocols for metabolomics on CSF samples have been proposed, used and evaluated. In addition, a new feature of data processing allowing new samples to be predicted into existing models has been tested, evaluated and used for metabolomics on blood and CSF. A panel of potential biomarkers has been generated for ALS and subtypes of ALS. An overall decrease in metabolite concentration was found for subjects with ALS compared to their matched controls. Glutamic acid was one of the metabolites found to be decreased in patients with ALS. A larger metabolic heterogeneity was detected among SALS cases compared to FALS. This was also reflected in models of SALS and FALS against their respective matched controls, where no significant difference from control was found for SALS while the FALS samples significantly differed from their matched controls. Significant deviating metabolic patterns were also found between ALS subjects carrying different mutations in the gene encoding SOD1.
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Applying Contact Angle to a Two-dimensional Smoothed Particle Hydrodynamics (SPH) model on a Graphics Processing Unit (GPU) PlatformFarrokhpanah, Amirsaman 22 November 2012 (has links)
A parallel GPU compatible Lagrangian mesh free particle solver for multiphase fluid flow based on SPH scheme is developed and used to capture the interface evolution during droplet impact. Surface tension is modeled employing the multiphase scheme of Hu et al. (2006). In order to precisely simulate the wetting phenomena, a method based on the work of Šikalo et al. (2005) is jointly used with the model proposed by Afkhami et al. (2009) to ensure accurate dynamic contact angle calculations. Accurate predictions were obtained for droplet contact angle during spreading.
A two-dimensional analytical model is developed as an expansion to the work of Chandra et al. (1991). Results obtain from the solver agrees well to this analytical results.
Effects of memory management techniques along with a variety of task assigning algorithms on GPU are studied. GPU speedups of up to 120 times faster than a single processor CPU were obtained.
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Applying Contact Angle to a Two-dimensional Smoothed Particle Hydrodynamics (SPH) model on a Graphics Processing Unit (GPU) PlatformFarrokhpanah, Amirsaman 22 November 2012 (has links)
A parallel GPU compatible Lagrangian mesh free particle solver for multiphase fluid flow based on SPH scheme is developed and used to capture the interface evolution during droplet impact. Surface tension is modeled employing the multiphase scheme of Hu et al. (2006). In order to precisely simulate the wetting phenomena, a method based on the work of Šikalo et al. (2005) is jointly used with the model proposed by Afkhami et al. (2009) to ensure accurate dynamic contact angle calculations. Accurate predictions were obtained for droplet contact angle during spreading.
A two-dimensional analytical model is developed as an expansion to the work of Chandra et al. (1991). Results obtain from the solver agrees well to this analytical results.
Effects of memory management techniques along with a variety of task assigning algorithms on GPU are studied. GPU speedups of up to 120 times faster than a single processor CPU were obtained.
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Utvärdering av C6-peptid-baserad serologi på cerebrospinalvätska som komplement vid diagnostik av neuroborreliosKnaziak, Margareta January 2012 (has links)
Borrelios är den vanligaste fästingburna infektionen på norra halvklotet, och orsakas av spiroketer tillhörande Borrelia burgdorferi sensu lato-komplexet. Dessa bakterier kan spridas till flera organ och ge upphov till olika symptom i bland annat hud, nervsystem, leder och hjärta. Omkring 15 % utvecklar neurologiska symptom, så kallad neuroborrelios. Den bästa indikatorn på aktiv neuroborrelios är framförallt karakteristiska neurologiska symptom samt tecken på en inflammatorisk förändring i cerebrospinalvätskan (CSV) i kombination med lokalt producerade antikroppar mot Borrelia burgdorferi s.l. i CSV. Nuvarande metod för diagnostik av neuroborrelios är en immunokemisk metod, en ELISA (enzyme-linked immunosorbent assay) som bygger på en jämförelse av Borrelia-antikroppsnivåer i CSV och i serum genom beräkning av antikroppsindex (AI). Beräkning av AI kompenserar för en eventuell ospecifik överföring av antikroppar från serum, till följd av en skada på blod-hjärnbarriären. Det finns dock tecken på att den nuvarande analysmetoden har för låg sensitivitet med falskt negativa resultat, framförallt tidigt i infektionsförloppet. För diagnostik av andra former av borrelios än neuroborrelios används en typ av ELISA baserad på C6-peptid. C6-peptid ELISA visar god känslighet för detektion av B. burgdorferi s.l.-specifika antikroppar i serum. C6-antigenet utgör en starkt immunogen och konserverad region av bakteriens VlsE-ytprotein. Syftet med den här studien var att undersöka om detektion av antikroppar mot C6-peptid i CSV kan komplettera den nuvarande använda metoden och därmed förbättra den totala sensitiviteten för diagnostik av neuroborrelios. I studien analyserades 169 patientprover från unga personer, samt 18 oklara patientfall som tidigare bedömts negativa med den nuvarande metoden. Antikroppar mot C6-peptid detekterades hos åtta unga patienter samt två oklara patientfall. Av dessa hade åtminstone tre unga patienter sannolikt neuroborrelios. Resultat från den här studien tyder på att C6-peptid-ELISA på CSV-prover kan fungera som ett komplement till befintlig metod för diagnostik av neuroborrelios. En kombination av båda metoderna kan sannolikt ge en betydligt högre sensitivitet. Vid tolkning av resultat från C6-peptid-baserade analysmetoder på CSV ska hänsyn tas till eventuell ospecifik överföring av B. burgdorferi s.l.-specifika antikroppar genom blod-hjärnbarriären. / Lyme Borreliosis, caused by spirochetes of the Borrelia burgdorferi sensu lato-complex, is the most common tick-borne infection in the temperate regions of the northern hemisphere. The bacteria can infect many different organs, this can give rise to a variety of symptoms in skin, the nervous system, joints and heart. Approximately 15 % of the infected individuals show neurological symptoms referred to as neuroborreliosis. An active neuroborreliosis is indicated by inflammatory changes in the cerebrospinal fluid (CSF) and local synthesis of anti-Borrelia antibodies in CSF. The current method to diagnose neuroborreliosis is an enzyme-linked immunosorbent assay (ELISA) which compares levels of anti-Borrelia antibodies in CSF and serum by calculating an antibody index (AI). Calculations of AI compensate for unspecific leakage of antibodies from serum to CSF following an injury of the blood-brain barrier. The drawback of the current method is a low sensitivity with a high rate of false negative results in samples collected early during an infection. Another type of ELISA, based on the use of a C6 peptide, has earlier shown good sensitivity for detection of B. burgdorferi s.l.-specific antibodies in serum. The C6 antigen corresponds to a highly immunogenic and conserved region of the bacterial surface protein VlsE. The aim of this study was to investigate whether a detection of antibodies against the C6 peptide in CSF could improve the total sensitivity for the diagnostics of neuroborreliosis. In the current study, 169 samples with negative AI from young patients and 18 samples from special cases were analyzed. Antibodies against the C6 peptide were found in 8 young patients and in 2 samples from special cases. Out of these, 3 young patients were stated positive for neuroborreliosis. Results of this study show that the C6 peptide ELISA on CSF samples could act as a complement to the current serological method for diagnosing neuroborreliosis. A combination of both methods could possibly increase the overall sensitivity. However, the blod-brain barrier injury issue is a problem in the analysis and interpretation of the results of the C6 peptide-based method on CSF should take into consideration a possible dysfunction of the blood-brain barrier. In conclusion, a combination of both the current method and the C6 peptide ELISA could give a markedly improved sensitivity in diagnostics of neuroborreliosis.
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Critical Success Factors (CSFs) in Enterprise Resource Planning – Commercial Off the Shelf (ERP-COTS) Software ImplementationSiddique, Muhammad Shoaib January 2009 (has links)
<p>The focus of the study is to identify ERP COTS software where custom made ERPP and COTS software are different in product type and implementation process. The study further intensifies the focus on the factors which are critical for successful ERP COTS product selection and implementation by decision makers and ERP COTS implementers respectively.</p><p>The study involves decision makers, management and organizational actors (end users which are beneficiaries of ERP COTS system). The study tries to identify certain factors, which can lead to the success of the ERP COTS Software implementation and failure to identify those CSFs in selecting and implementing ERP COTS can lead to ERP COTS failure.</p>
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