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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.
21

Investigation of the effects of cigarette smoke on immunoglobulin levels in serum and saliva samples of smoker and non-smoker subjects using antibody-microarray technology

Tarbiah, Nesrin January 2017 (has links)
Cigarette smoke (CS) has many damaging effects on the body, and the chronic inhalation of cigarette smoke can change immunological functions through impact on both innate and adaptive immunity. The incidences of many diseases are affected by the adverse effects of cigarette smoke on the immune system, and the induction of an inflammatory response, which affects several tissues and organs. On this basis, a comparison of smokers′ and non-smokers′ immunoglobulin levels could provide valuable insights into the mechanisms of smoking related diseases. Although the effects of cigarette smoking on humoral and cellular immunity have been investigated previously, the results have varied between the studies, and therefore more research is still required. The aim of this study was to determine whether the levels of immunoglobulin (Ig) isotypes are different in the serum and saliva of non-smoking individuals compared to smoking individuals. An examination of serum and saliva would provide information on the effects of cigarette smoke systemically and in the oral mucosa, respectively. The effects of cigarette smoke extract on B-cell secretions were also examined to establish whether cigarette smoke components can have direct effects on immunoglobulin production by B cells. In order to determine Ig isotype levels, antibody microarray techniques were established and calibrated for determining the sample concentrations of IgM, IgG, IgA and IgD. The results showed that smoking has different effects on systemic and salivary immunoglobulin levels. In the serum, smokers had decreased levels of IgG and IgD, but increased IgM and IgA levels compared to non-smokers. However, in the saliva smokers had decreased levels of IgG, IgD, and IgM, whereas there were increased levels of IgA in smokers’ saliva. As CS has been found to influence the serum and salivary levels of Ig isotypes ex-vivo, the mechanisms underlying these effects were investigated in vitro to determine whether the changes were as a result of a direct effect of the CS on B-cells. This study has shown that CS had deleterious effects on the production and the levels, of Ig isotypes. These results support the concept that CS is related to diseases, and more research is necessary in this field.
22

The role of endocannabinoids in Alzheimer's disease

Maroof, Nazia January 2013 (has links)
The endocannabinoid system (ECS) comprises the endocannabinoids (ECs), including anandamide (AEA) and 2-arachidonoyl glycerol (2AG), which interact with the G protein-coupled type-1 and type-2 cannabinoid receptors(CB1 and CB2 respectively). The ECS is thought to have a role in a number of central processes including neuroinflammation, neurogenesis, neuroprotection, learning and memory. Due to its influence on a diverse number of processes, it has been suggested that modifying the ECS may be therapeutically beneficial in Alzheimer's disease (AD). AD is an age-related neurodegenerative disorder characterised by the presence of extracellular amyloid beta (Ab) plaques and intracellular neurofibrillary tangles (NFTs) resulting in impairments in learning in memory. The aim of this thesis was to determine the status of the brain ECS in the APPswe/PS18E9 mouse model of AD and wild type littermates at 4, 6 and 8 months of age and the performance of these animals in a behavioural test battery. The results of this study indicated that APPswe/PS18E9 animals were hyperactive compared to their wildtype counterparts at all ages and that they also displayed deficits in behavioural flexibility. EC levels increased with age in both wild type and APPswe/PS18E9 mice. Cannabinoid receptor coupling was increased in the frontal cortex and striatum of APPswe/PS18E9 mice relative to wildtype. This study concluded that the status of the brain ECS is altered in AD. Modifications to the performance of the ECS were made in the form of chronic administration of a CB1 receptor antagonist (SR141716A1rimonabant) and a CB2 receptor agonist (JWH133). Chronic administration of SR141716A was able to reverse some learning impairments in APPswe/PS18E9 animals. In contrast, chronic administration of JWH133 resulted in impaired memory extinction in both wildtype and APPswe/PS18E9 mice. The results support the potential benefit of modulating the endocannabinoid system in the treatment of memory impairment in AD.
23

The effects of cannabinoids on insulin secretion

Anderson, Richard L. January 2011 (has links)
Type 2 diabetes mellitus is a chronic condition caused by a deficiency in the secretion of insulin from the islets of Langerhans and/or impaired insulin signalling, resulting in hyperglycaemia. The role of the endocannabinoid system is well-recognised in the CNS and immune system, but its role in glucose homeostasis is poorly understood. The aim of this study was to define the roles of cannabinoids in insulin secretion, to provide insights into their therapeutic potential (or limitation) in the treatment of type 2 diabetes. Isolated islets were used, from Wistar rats, in static incubation studies measuring changes in insulin secretion rates. The endocannabinoid anandamide (AEA) was found to inhibit insulin secretion in a glucose- and concentration-dependent manner, with an IC50 of 1.6μM (95% CI: 227nM to 4.0μM; n= 10). Upon further analysis of the concentration-response data islet sensitivity to AEA appeared to vary, with islets either appearing to be sensative (IC50 220nM; 95% CI: 21.9nM to 2.2μM; n= 5) or less sensative (IC50 12.3μM; 95% CI: 6.8μM to 19.4μM; n= 5) to AEA. Pre-incubation of islets with a fatty acid amide hydrolase inhibitor did not affect islet responsiveness to AEA. AEA-mediated inhibition of insulin secretion was not consistently affected by cannabinoid receptor 1 (CB1) or CB2 antagonism. Surprisingly, the CB1 receptor antagonist AM251 was found to inhibit insulin secretion in a glucose- and concentration-dependent (IC50 1.6μM; 95% CI: 507nM to 3.3μM; n= 6) manner. Results from this study suggest that differences in CB-receptor signalling pathways, rather than endocannabinoid metabolism, could be responsible for the variations in the potency of AEA between islet preparations. Characterisation of cannabinoid signalling in islets was hindered as the CB receptor antagonists used in this study also affected insulin secretion. This study highlights the dynamics of endocannabinoid signalling in islets, which may be linked to their physiological function.
24

Deskriptive Ergebnisse der Organisationsstudie "Arbeitsmarktpolitische Bildungsmaßnahmen in Österreich 2006"

Schedlberger, Markus, Schneider, Ulrike, Trukeschitz, Birgit, Irmer, Manon January 2007 (has links) (PDF)
Series: Forschungsberichte / Institut für Sozialpolitik
25

Neuropharmacological properties of the cathinones

Shortall, S. E. January 2015 (has links)
At the height of its popularity, mephedrone was the most common recreationally used cathinone. This is thought to be due to its perceived likeness to MDMA. Therefore the aim of this thesis was to examine mephedrone-induced changes in behaviour, body temperature or neurochemistry in the rat and to compare these changes to those observed following MDMA administration. This was achieved by assessing changes in body temperature following acute mephedrone, MDMA, cathinone or methcathinone administration. Additionally, locomotor activity and cognitive tasks were performed following chronic intermittent administration of mephedrone, MDMA or cathinone. These behaviours, as well as mephedrone-induced changes to body temperature and ‘anxiety-related’ behaviour, were also assessed following either pre-treatment with MDMA or co-administration of caffeine. Finally, locomotor activity, body temperature changes and in vivo striatal dopamine release were assessed following rapid repeated dosing of mephedrone, and the roles of dopamine, 5-HT and noradrenaline in these responses were examined. Post mortem monoamine concentrations from specific brain regions were also assessed following acute, chronic intermittent and rapid repeated dosing of mephedrone. It was found that the neurochemical, behavioural and physiological effects of mephedrone in the rat include hyperactivity, hypothermia, cognitive deficits, anxiety-related behaviour and increased striatal dopamine efflux. Pre-exposure to MDMA, or concomitant caffeine administration, caused an increase in rectal temperature following mephedrone injection while caffeine co-administration prolonged the hyperactive profile of mephedrone. Importantly, unlike MDMA, rapid repeated mephedrone administration (3 x 10 mg kg-1 at 2 h intervals) had no cumulative effect on mephedrone-induced hypothermia or hyperactivity. It is also clear that mephedrone is inducing its effects via noradrenergic, dopaminergic and serotonergic mechanisms. The cathinones and MDMA had varying effects on post mortem tissue levels of the monoamines and their metabolites. Importantly, these effects of mephedrone appear to be occurring by mechanisms that are different, but similar, to MDMA.
26

Entwicklung eines Instruments zur Messung des Nutzens betrieblicher Zusatzleistungen aus der Sicht von Mitarbeiterinnen und Mitarbeitern

Enthammer, Markus 04 May 2012 (has links) (PDF)
Im Rahmen der Diskussion zu den immer höher werdenden Personalkosten , vor allem in Deutschland und Österreich, ist die Gewährung von betrieblichen Sozial- und Zusatzleistungen in Unternehmen nach dem Gießkannenprinzip nicht mehr zeitgemäß und kosteneffizient. Dem entgegen wirken würde eine individualisierte und bedürfnisorientierte Vergabe von Zusatzleistungen an die Mitarbeiterin bzw. an den Mitarbeiter, ausgerichtet an deren bzw. dessen jeweiligem Nutzenempfinden. Erwartet wird hierbei eine äußerst heterogene Nutzen- bzw. Präferenzstruktur unter den MitarbeiterInnen, beeinflusst von Faktoren wie Sozio- und Demographie. Das Ziel dieser Arbeit ist die Entwicklung einer Methode, die es den Unternehmen selbst ermöglicht, Präferenzmessungen betrieblicher Zusatzleistungen, basierend auf unterschiedlichen Mitarbeitertypen, durchzuführen bzw. die Ergebnisse dieser Messungen zu verwenden, um das Zusatzleistungsportfolio bedürfnisgerecht zu optimieren bzw. diejenigen Leistungen aufzunehmen, von denen erwartet werden kann, dass sie den höchsten Nutzen für die in diesem Unternehmen beschäftigten MitarbeiterInnen (bzw. Mitarbeitertypen) stiften. Zusätzlich wird versucht, eine Quantifizierung und eine Monetarisierung der Präferenzvorstellungen betrieblicher Zusatzleistungen durchzuführen, in dem eine geldwerte Komponente in die Messung mit aufgenommen wird. (Autor/inn/enref.)
27

What Determines the Quality of Job Training Services? A Multi-Level Analysis for Austria.

Trukeschitz, Birgit, Schneider, Ulrike January 2008 (has links) (PDF)
Within the last few decades, the provision of social services was and still is changing in many ways: due to ideological changes and cost containment efforts, the public sector has been gradually withdrawing from his dual role as financier and provider of social services. The public sector now prefers acting as a financier rather than a provider. It purchases services on behalf of service users, while private sector organizations assume the responsibility for service provision. Recently, European rules for public procurement policies and the efforts to liberalize service markets have promoted changes in the funding relationship between public entities on the one hand and nonprofit or forprofit organisations on the other hand. Increasingly, in terms of instruments the public sector follows a contractual approach to managing its relationship with private and nonprofit organizations. Performance related forms of funding are becoming gradually more important whereas funding via grants is on the decline. Moreover, modes of public procurement are relying more heavily on competitive processes. (...) (author´s abstract) / Series: Working Papers / Institut für Sozialpolitik
28

Calcium homeostasis in the elderly

Thompson, Shirley Patricia January 1989 (has links)
The initial aims of this investigation were to develop a reliable assay system for measuring serum 1,Z5-dihydroxyvitamin D [1,Z5(OH)ZD] concentrations and to establish a normal range in young healthy adults. Compared with young healthy individuals, the elderly population are indeed vitamin D deficient. Vitamin D deficiency was also demonstrated in a group of elderly osteomalacic patients. Slight improvements in osteomalacia was achieved by one month of treatment with vitamin D3' or alphacalcidiol with or without calcium supplements. The improvements were small and occured slowly. A significant increase in the strength of bone seems unlikely to occur in the short term. On the present evidence the combination of alphacalcidiol and calcium supplements seems no better than vitamin D3 or alphacalcidiol alone although it may require closer monitoring to avoid hypercalcaemia. In a group of elderly patients with osteoporosis and femoral neck fracture (FNF), serum osteocalcin concentrations rose significantly in the first week after fracture fixation. The change in osteocalcin correlated well (p < 0.001) with the change in serum 1,Z5(OH)ZD concentration. Histomorphometric measurements of the extent of osteoid correlated better with osteocalcin than alkaline phosphatase. Serum concentrations of 1,Z5(OH)ZD were also reduced in elderly patients with FNF irrespective of the presence of osteomalacia and therefore cannot be used as a screening test for osteomalacia in this patient group. Reduction of 1,Z5(OH)ZD was not due to a reduction in vitamin D binding protein. It is suggested that the low rate of bone turnover in these elderly patients reduces the requirement of vitamin D. Of the ten elderly patients who had underwent laryngo pharyngeal surgery all developed hypocalcaemia. This immediate post-operative decrease, due to a rapid reduction in circulating PTH concentrations, lead to an overall increase in urinary calcium excretion. Serum concentration of 1,25(OH)2D also fell postoperatively thus potentiating the hypocalcaemic state in these patients. Thus, it is important to give parenteral feeding supplemented with calcium and vitamin D, preferably alphacalcidiol. If delayed then profound as well as prolonged hypocalcaemia can occur. The human osteosarcoma cell 20S metabolised 25(OH)D3 in a substrate concentration and time dependent manner to produce products which were secreted into the extracellular medium. These products eluted from HPLC with a retention time coincident with 24,25(OH)2D3 and exhibited an UV absorption spectrum characteristic of a vitamin D sterol. Mass spectroscopy analysis indicated at least two products were synthesised by the cells. One was identical to 24,25(OH)2D3; the other appeared to be an unsaturated trihydroxylated derivative of vitamin D3.
29

The cardiovascular profile and pharmacology of vandetanib and pazopanib

Carter, Joanne January 2017 (has links)
Angiogenesis, a process that enables the growth of blood vessels from a pre-existing vasculature and is common to all solid tumours greater than 1 mm3 in size (Gacche and Meshram, 2014). The angiogenic process is heavily promoted by vascular endothelial growth factor (VEGF). Compounds able to inhibit VEGF signalling have been shown to reduce cancer mass (Arjaans et al., 2016). However, VEGF receptor tyrosine kinase inhibitors (RTKIs), a class of anti-VEGF treatment, have been shown to cause cardio-toxicity, with hypertension being a commonly reported, and often severe, side effect (Eskens and Verweij, 2006; Widakowich et al., 2007; Abi Aad et al., 2015). Depending on the nature of the study, the incidence of hypertension in the VEGF RTKI patient population ranges from 23% to 90% (Hamberg et al., 2010; La Vine et al., 2010; Aparicio-Gallego et al., 2011; Bible et al., 2014). Due to the increasing incidence and seriousness of hypertension observed in oncology clinics, it is clear that there are important cardiovascular issues relating to the use of RTKIs, particularly those that target VEGF, that require further exploration. This body of work set out to determine the in vitro potencies of vandetanib, pazopanib, cediranib and sorafenib at VEGFR2, alongside the in vivo cardiovascular haemodynamic and vasoactive profile of vandetanib and pazopanib, two VEGF RTKIs shown to cause hypertension in approximately 32% (Wells et al., 2012) and 33%-40% of the patient population, respectively (Bible et al., 2014). In NFAT luciferase assays cediranib, sorafenib, pazopanib and vandetanib were shown to inhibit, in a non-competitive fashion, VEGF165 mediated signalling in vitro. In haemodynamic studies, using Doppler flowmetry and telemetry methodologies, both vandetanib and pazopanib caused significant hypertension (P < 0.05, in comparision to vehicle). Pazopanib and vandetanib lead to significant vasoconstriction of the mesenteric and hindquarter vascular beds, pazopanib also produced significant vasoconstriction in the renal vascular bed (P < 0.05, in comparision to vehicle). None of the variables measured in the haemodynamic studies significantly differed between the 30 mgkg-1day-1 pazopanib and 25 mgkg-1day-1 vandetanib groups. In chronic radio-telemetric studies, vandetanib was shown to cause a significantly greater but more transient increase in mean arterial blood pressure in comparison to pazopanib (P < 0.05). Vandetanib was also shown to inhibit VEGF and ACh-mediated vessel dilatation in pressure myography experiments. Finally, vandetanib and pazopanib were shown to induce vasodilatation in the presence of a vasoconstrictor (U46619), a previously unseen finding. In conclusion, the body of work undertaken here has given novel insight into the ability of non-competative anti-VEGF RTKIs to inhibit VEGF-mediated signalling and vessel dilatation as well as produce direct effect of vessel diameter in the absence of VEGF. It has also produced a validated method of hypertension in a rat model, both in the short and long term. These models have shown that different anti-VEGF RTKIs have different regional haemodynamic and post-treatment hypertensive side effect profiles. These findings are important for understanding the mechanisms behind the therapeutic and non-therapeutic effects of VEGF RTKIs and allow for further research into the signalling mechanism involved in VEGF RKTI-mediated hypertension and the potential therapeutic treatments that could treat this.
30

Implementation and optimisation of alternative therapeutics for use in Clostridium sporogenes as a delivery vehicle

Budd, Patrick G. January 2017 (has links)
Clostridium sporogenes is part of a highly diverse group of Gram positive, spore forming, anaerobic bacteria. C. sporogenes can be used as a delivery vehicle for chemotherapeutics in cancer treatment due to the inactive spore form of C. sporogenes only germinating in the microenvironment of the hypoxic tumour. Cancer, despite large investment in treatment and diagnosis, still remains one of the leading causes of death in the world. As such, improvements on current treatments are necessary to improve patient prognosis. Utilising C. sporogenes could be a cheap and effective way to do this by utilising their germination properties to deliver anti-cancer therapeutics directly to the hypoxic regions of solid tumours. Through introducing Prodrug Converting Enzymes (PCEs) into C. sporogenes when the spores germinate in the tumour the production of the PCE will result in the breakdown of a Prodrug into a toxic product resulting in an anti-cancer effect. This system is known as Clostridial Directed Enzyme Prodrug Therapy (CDEPT). Previous iterations of this system incorporated a nitroreductase gene, used for the breakdown of the prodrug CB1954. During this project alternative prodrugs were investigated, in this case carboxypeptidase G2. Alternatives into the prodrug and enzyme system are also being investigated in a direct action therapy in the form of the monoclonal anti-VEGF. The aims of this project were to implement the genes and optimise the activity of the drugs if necessary. It was also necessary to confirm that the bacterium was a non-pathogenic group 1 bacterium through sequencing and annotation of the genome.

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