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Molecular modelling of the cannabinoid receptors : structure-based design, synthesis and pharmacological evaluation of novel ligands based on the fenofibrate scaffoldLoo, Jason S. E. January 2015 (has links)
The cannabinoid receptors CB1 and CB2, which belong to the rhodopsin family of GPCRs, are implicated in the pathology of various disease states. As drugs targeting these receptors remain limited, novel cannabinoid receptor ligands represent an unmet need with substantial therapeutic potential. We present here the construction and application of homology models of the human CB1 and CB2 cannabinoid receptors based on the crystal structure of the human adenosine A2A receptor for the structure-based design of novel ligands based on the fenofibrate scaffold. Models were refined through molecular dynamic simulations in a lipid bilayer, and were validated via the prediction of known ligand binding affinities, enrichment studies and assessment of predicted ligand binding modes. These validated models were subsequently used in predicting the binding mode of fenofibrate derivatives to the cannabinoid receptors. The predicted binding mode of these fenofibrate derivatives to the CB2 receptor showed good agreement with known mutagenesis data, indicating the binding of these compounds to be stabilized primarily by hydrogen bonds with W5.43 and C7.42, aromatic stacking with F2.57, F3.36 and W6.48, and hydrophobic contact with F2.64, V3.32 and I5.47. A series of novel ligands was derived based on these findings, docked into our model, synthesized and pharmacologically evaluated at the CB2 receptor. The pharmacology of these ligands validated our modelling predictions and binding mode hypothesis, with several of these ligands showing unique pharmacology by binding in an allosteric manner. These findings may be used to guide the design of further derivatives and highlight the promise of the fenofibrate scaffold in the development of novel CB2 receptor ligands.
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Body image and weight management : young people, internet advertisements and pharmacistsLuevorasirikul, Kanokrat January 2007 (has links)
Media promotion of the ideal body as slimness for women and muscularity for men, has led to increasing numbers of both genders reporting dissatisfaction with their bodies and trying to change using weight control products. It has been suggested that pharmacists can play a key role in promoting healthy lifestyles and weight management. The main aim of the research study was to examine the impact of media on body image perception and to investigate the role of pharmacists in weight management. This thesis consists of three studies: an evaluation of weight control websites, a body image survey of young adults and interviews with pharmacists. The results from the evaluation study showed that the quality of most weight loss (64%) and weight gain product advertisements (80%) was generally poor, principally due to the use of misleading claims and a lack of useful information. These data complement the survey that university students reported rarely being influenced by weight control product adverts and hardly considered using these products as a method for changing weight. The survey also showed that most participants of both genders (71%) felt satisfied with their body image. However, the findings in this study indicated that there was a relationship between a high level of body image concern and self-perception of being overweight and the attempt to lose weight. Interviews with pharmacists showed that they were unlikely to be actively involved in reducing obesity problems and promoting healthy lifestyles in the community. Although the prevalence of body dissatisfaction and the use of weight control products among these young adults may not be as high as has been reported elsewhere, healthcare professionals, including pharmacists, need to be aware of this problem when providing advice or consultations for young adults. Healthcare professionals should promote the benefits of healthy lifestyles as well as providing information about potential problems of harmful weight control strategies. The effect of ethnicity and culture on body image concern warrants further. The availability of weight control products and quality of information provided should also be further examined.
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Studies into solid core drug delivery system using haemoglobin as a model drug and supercritical fluid processing for encapsulationBhomia, Ruchir January 2015 (has links)
The aim of this project was to formulate a solid core drug delivery system for oral delivery of proteins using silica as core material, haemoglobin as model drug and supercritical fluid processing as encapsulation technique. Silica particles of different morphology were used as a carrier material for protein immobilisation and fatty acids coating was performed using supercritical carbon dioxide (CO2) as a processing media. The melting behaviour of saturated fatty acids (lauric, myristic, palmitic and stearic acid) and pluronics (F-38, F-68, F-77, F-127 and F-108) were studied under pressurised CO2 to identify the coating parameters. These excipients showed a melting point depression in the range of 10 to 20 °C in pressurised CO2. In the case of fatty acids the decrease in melting point was inversely proportional to the carbon chain length and directly related to the polarity of carbonyl group. Whereas, melting point depression for all pluronics was similar and was attributed to the high cohesive energy density of these polymers. This phenomenon was used to encapsulate the thermolabile protein molecules in pressurised CO2 at low temperatures. The stability of bovine haemoglobin (bHb) was studied by ultraviolet-visible and circular dichroism spectroscopy. Thermal, storage and agitation stability were studied to identify the processing parameters for the storage, adsorption and desorption processes. Three morphologically different silica particles were studied as potential inorganic carrier for the protein. The particles were characterised by nitrogen adsorption and scanning electron microscopy and the maximum protein adsorption and kinetics was determined at pH 6. The bHb adsorption on silica was found to be irreversible, hence application of pluronics as a displacer was also studied. Finally, the bHb adsorbed particles were coated with fatty acids by supercritical fluid processing and solvent evaporation methods. The highest bHb release was obtained from SFP (Syloid FP-244) silica in comparison to other silica particles in pH 6.8 phosphate buffer. SFP based formulation also showed a trend in the protein release which was dependent on the solubility of fatty acids in the release media. The highest release was obtained from myristic acid coated solid core drug delivery system (SCDDS) followed by palmitic and stearic acid. Lauric acid coated SFP formulations led to changes in protein conformations, hence omitted from these studies. The release studies of myristic acid based SCDDS in simulated gastric and intestinal fluids showed that fatty acid coating provided enteric properties to the formulation. It can be concluded from these studies that SCDDS prepared using mesoporous silica as core and fatty acids as coating material can be an effective drug delivery system for the oral delivery of biomolecules.
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Assessment of drug-loaded nanoparticles in a 3D in vitro brain tumour modelIvanov, Delyan Pavlov January 2015 (has links)
This work describes the creation of a three-dimensional model of the children’s brain tumour medulloblastoma using primarily human cells. This in vitro cell culture model was created as a platform for testing novel drug delivery systems for local delivery in the brain. The aim of the local delivery strategy was to reduce radiotherapy through the use of nanoparticle-based chemotherapy. The nanoparticles would be delivered after surgery in the cavity left by the excised tumour tissue. The model was intended to evaluate the selective cytotoxicity of advanced drug delivery systems towards tumour tissue and the benefit of nanoparticle therapy compared to free drug. Normal tissue was modelled using human foetal brain tissue and tumour tissue was represented by a variety of medulloblastoma cell lines. Both were cultured as three-dimensional spheroids free of artificial matrix in ultra-low attachment plates. The tumour and normal cells could be cultured either separately or together and the viability for each cell population determined using a battery of methods. Co-cultures of both cell types had the additional benefit of mimicking the interaction between normal and tumour tissue. The use of physiologically relevant single and co-culture in vitro models could provide information on the relative safety and efficacy of novel brain tumour treatments. The high-throughput platforms used, the algorithms and the validation of a battery of tests in 3D may be extrapolated to other cancer models as well. Moreover the universal marking procedure employed can be employed to label, culture and analyse any two cell types, while preserving tissue heterogeneity and viability. The key benefit from this thesis is the framework for designing in vitro models of tumours that include normal tissue as an internal control. This is an important contribution that can substantiate IC50 values by putting them in the context of drug safety and efficacy. It also highlights the minimum checks and feasibility experiments that need to be done before an in vitro assay is accepted for 3D spheroids.
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Structural modification of Clusianone from Garcinia parvifolia and in vitro evaluation targeting microtubule system of respiratory carcinomaNagalingam, Sree Vaneesa January 2017 (has links)
Clusianone isolated from Garcinia parvifolia has been studied for its anticancer properties and cytotoxicity to human respiratory cells. The clusianone was first isolated using solvent extraction, column chromatography, thin layer chromatography and finally recrystallization method through solvent evaporation including seed crystal to induce crystal growth of clusianone. The clusianone was characterized using X-ray crystallography, ESI-MS, NMR and melting point. During the course of this research, clusianone was chemically modified and eight different derivatives abbreviated as CMet, CHyd, CMxA, CMeA, CEtA, CPryl, CGeryl and CDMet were obtained. Some of the chemical methods employed were hydrogenation, methylation, demethylation, ketone reduction via addition of amine derivatives and O-alkylation to install additional prenyl and geranyl chain into clusianone. Further studies of the role of the clusianone derivatives were presented in its in vitro anticancer activity. The anticancer test and cytotoxicity effect were tested using MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)assay. Specific normal human and cancer cell lines were used in the assay being MRC5 (lung fibroblast), A549 (lung adenocarcinoma), NP69 (nasopharyngeal epithelial cell) and HK1 (squamous carcinoma of the nasopharynx). Preliminary study of clusianone and derivatives showed cytotoxicity effect in dose dependent manner. Based on the results, clusianone and compound CMeA demonstrated good anticancer activity showing IC50 values below 5 μM against A549 and HK1 cancer cells and at the same time affecting less of the MRC5 and NP69 normal cells. Western blot method was employed to further elucidate the downregulation of the protein expression of β-tubulin including cell cycle regulators Cdk1 and cyclin B1 for clusianone and CMeA derivative treated carcinoma cells. Clusianone and compound CMeA demonstrated potential antimicrotubule agent characteristic since expression of β-tubulin and cell cycle regulators Cdk1/cyclin B1 were downregulated in A549 cells. As for HK1 cells, clusianone downregulated β-tubulin protein without affecting Cdk1 and cyclin B1 expression. In contrast, compound CMeA showed prominent downregulation of β-tubulin, CDK1 and cyclin B1 proteins especially after 48 hours treatment in HK1 cells.
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Molecular expression of recombinant Apoptin in planta and preliminary evaluation of biological characteristics of plant-made Apoptin on cancerous cellsChan, Xiao Ying January 2017 (has links)
Apoptin, a potential anticancer candidate, selectively kills tumour or transformed cells but remains harmless to normal and non-transformed cells. Besides, apoptin-induced apoptosis is independent of p53 apoptosis pathway, which is always mutated in cancer cells during tumorigenesis or after radiotherapy. This has made apoptin becoming more pharmacological valuable. In this study, the general aim was to develop a plant-derived apoptin which offers a safer and more cost-effective treatment for cancer patients. The scope of the study focused on the production of recombinant apoptin in a plant-based system and preliminary bioactivity evaluation of the purified plant-derived apoptin on human lung cancer adenocarcinoma A549 cells. Recombinant apoptin was expressed in Nicotiana benthamiana as apoptin alone, in fusion to green fluorescent protein (GFP) as well as in fusion to lichenase (Lic) to increase the expression of recombinant protein in soluble fraction. Recombinant apoptin was also in fusion to H22 single chain antibody and epidermal growth factor (EGF) in order to target recombinant H22-apoptin and EGF-apoptin to cancer cells overexpressed with immunoglobulin G (IgG) receptor (CD64) and EGF receptors. Expression of recombinant apoptin was detected in N. benthamiana successfully, however, high amount of soluble protein was obtained in plants infiltrated with recombinant GFP-apoptin (gene casette: PR-GFP-VP3-HK) and EGF-apoptin (gene casette: PR-EGF-CatAd-VP3-HK) that targeted the recombinant proteins to endoplasmic reticulum (ER). Protein purification using immobilised metal affinity chromatography (IMAC) recovered recombinant GFP-apoptin (GFP-VP3-HK) and EGF-apoptin (EGF-CatAd-VP3-HK) at a low purity when recombinant proteins were purified in a non-denaturing condition. Host cell protein contamination was not able to be removed when second chromatography and acid precipitation method were used. However, recombinant GFP-apoptin (GFP-VP3-H) and lichenase-apoptin (Lic-VP3-H) without targeted to specific cellular compartment were purified at a good purity using IMAC. Recombinant GFP-VP3-H extracted in a denaturing condition was successfully refolded without an addition of chemical additives while recombinant Lic-VP3-H required triton to refold the protein. In cell-based study, enzyme-linked immunosorbent assay (ELISA) showed that apoptin interacted with EGF receptors as well as A549 cells which finding is the first of its kind in report but with an unverified speculation. On the other hand, nuclear localisation activity and a few apoptosis-associated morphological features were observed in cells microinjected with recombinant GFP-VP3-H. Meanwhile, recombinant EGF-VP3-HK showed a dose-dependent growth inhibitory effect at higher concentration and caused the loss of mitochondrial membrane potential (MMP) in treated A549 cells. However, internalisation of recombinant EGF-VP3-HK requires a further study for confirmation. Considering the findings on MMP and caspase 3/7 assays were not convincing enough, further evaluations are necessitated in order to verify the apoptosis events induced by the recombinant GFP-VP3-H and EGF-VP3-HK. Nonetheless, this study has heralded a new milestone for apoptin research by which its protein has been successfully produced in plants and some preliminary biological characteristics have been explored at a certain extent.
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Examining the impact of CDSS on antibiotic use in hospitalsAl Bahar, Fares January 2018 (has links)
Computerised clinical decision support systems (CDSS) are information technology tools used to optimise the use of antibiotics. A systematic review and meta-analysis was conducted to review the level of evidence of the impact of CDSS on antibiotic prescribing using specific outcome measures. Overall, CDSS interventions were associated with an increase in adequacy of antibiotic coverage based on a random effects model [OR = 2.11, 95% CI, 1.67 to 2.66, p ˂ 0.00001]. Results showed that CDSS had a marginal statistically significant effect on mortality based on a random effects model. [OR = 0.85, 95% CI, 0.75 to 0.96, p = 0.01]. Medical and non-medical healthcare professionals in University Hospitals Birmingham Foundation Trust were surveyed about their perceptions and attitudes towards CDSS. 85% participants showed a positive attitude towards CDSS. A quantitative retrospective before-and-after study in the University Hospitals Birmingham Foundation Trust was conducted from June 2012 to June 2016 to measure the impact of a CDSS tool known as Structured Prescribing on the volume of antibiotic use. From June 2012 to June 2016, the total antibiotic usage increased by 13.1% from 1436.3 to 1624.85 DDD/1000 bed-days. CDSS show demonstrable potential in optimising the use of antibiotics and containing antimicrobial resistance.
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Pro-drug strategies for pancreatic cancer therapyAlfahad, Mohanad Abdul-Satar Mahmood January 2018 (has links)
Pancreatic cancer is the fourth main cancer in the western world. Currently the only chemotherapy available clinically is gemcitabine. However, gemcitabine treatment only proves effective in 23.8% of patients. Nano-structures (< 120 nm) are capable of entering the highly permeable blood capillaries which supply the rapidly growing tumours. Once inside the capillaries they accumulate and are retained in the tumour as a result of the poor lymphatic drainage. This allows for a deeper tissue penetration which is otherwise difficult to achieve. Hybrid nanoparticles with an iron oxide core covered by gold shell (HNPs) have shown great potential for anti-cancer therapies. The magnetic iron oxide cores and the surface plasmon resonance (SPR) properties of the gold surface provide the HNPs with the capabilities of diagnostic imaging and drug delivery, making them true theranostic agents. A novel prodrug of gemcitabine has been developed by a regioselective coupling of gemcitabine and lipoic acid, itself a potent antioxidant. Gemcitabine-N-lipoate (GL) was obtained in a one-pot synthesis and the optimum conditions for the reaction were established. GL prodrug loading on to the HNPs surface was confirmed and the release profile of gemcitabine from the GL-HNPs formulation was studied at pH 3.6, 5.6 and 7.4 utilising different temperature conditions (20, 37, 44 °C) using RPMI serum free media under sink conditions. The data showed the stability of the formulation at pH 7.4, 20 °C while the optimum release conditions for gemcitabine from the GL-HNPs formulation were at pH 5.6, 44 °C with the highest release of 41.1% recorded after 24 hrs. III Preliminary in vitro MTT assay together with the drug uptake study show the superior inhibitory effect of the GL-HNPs formulation on the cell viability over gemcitabine after 24 hrs which indicates faster uptake of the formulation, however the overall effect of gemcitabine is greater after 48 hrs which is mainly due to the slow release of gemcitabine from the formulation. The behaviour of the GL-HNPs formulation as a drug delivery system shows a great potential for the system to act as a theranostic tool and to overcome the significant drawbacks associated with gemcitabine.
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Towards monitoring of the progress of chemical reactions using a novel plasma-assisted desorption ionisation mass spectrometry methodologyJamur, Jasim Mohammed Shamar January 2018 (has links)
A novel method for monitoring of pharmaceutically relevant reactions using PADI-MS has been developed in this study. The visible non-thermal plasma plume from a coaxial helium gas flow non-thermal RF plasma was optimised using a range of samples. PADI-MS was found to be a powerful analytical technique for pharmaceutically relevant solid and liquid samples and can readily be adapted for use in reaction monitoring. This study has determined that PADI-MS is fast, easy to set up and requires little or no sample preparation. PADI-MS has significant advantages over other techniques as it is faster, more sensitive and more convenient and suitable for investigation of complex molecules and mixtures. However, two limitations of PADI-MS are that the plasma can affect the sample surface chemistry upon exposure and quantification is not always trivial. A number of other analytical methods were used in conjunction with PADI-MS: TLC, HPLC, FTIR and Raman spectroscopy. Chapter 3 investigated PADI-MS and Raman analysis of paracetamol tablet as model for pharmaceutically relevant solids. Raman microscopy was used to develop an understanding of how the plasma affects the sample surface. The plasma effect was also studied by examining changes in PADI-MS spectra. In Chapter 4, PADI-MS acquisition settings were improved by adding water vapour to the outer He flow gas and increasing the plasma power to 8 W, optimising the analysis of mixture solutions from TLC plates. Although molecules could be identified with optimum sensitivity after separation, this may not be necessary, unless the highest possible sensitivity is required. Chapter 5 deals with PADI-MS for direct analysis of pharmaceutical compounds in solid and liquid forms from glass slides and cotton swabs. PADI-MS was determined to besuitable for analysis of pharmaceutical tablets from solutions via both substrates, with distinct advantages for the latter. The final Chapter studied PADI-MS for the monitoring of imine formation as model pharmaceutical reaction. Both FTIR and PADI-MS were successfully used, but the latter is faster and more versatile. TLC and HPLC could not be used for this reaction. PADI-MS was successfully used for this reaction using cotton swabs without preparation or pre-concentration of sample solutions.
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Evaluation of the mevalonate pathway as a target for the treatment of ovarian cancerAbdullah, Marwan Ibrahim January 2018 (has links)
Ovarian cancer is the 5th leading cause of cancer-related death. The disease responds initially to treatment which is most often surgical cytoreduction followed by chemotherapy. The primary response rates to chemotherapy are approximately 80%. Unfortunately, most patients relapse and eventually tumours become refractory to frontline therapy. The lack of widely effective therapies at this points leads to a low 5-year survival. Therefore, new therapeutic agents or treatment strategies are required. It has been reported previously that gain of function mutations of p53 which upregulate the mevalonate pathway in breast cancer. TP53 is commonly altered in high grade serous ovarian cancer which might suggest that the mevalonate pathway may also be deregulated in ovarian cancer. The result reported in this thesis indicate that p53 upregulate the expression of key enzymes of the mevalonate pathway in ovarian cancer cell lines. In particular, it was found that 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGCR), the rate limiting enzymes of the pathway, geranylgeranyl transferase-I (GGTI), GGTII and farnesyltransferase are upregulated in number of ovarian cancer cell lines. These observations suggest that pharmaceutical inhibition of the mevalonate pathway may be a promising therapeutic approach. Pitavastatin, a member of statin family of HMGCR inhibitors, has been found to have significant activity against ovarian cancer cells and induce regression of ovarian cancer xenografts in mice in previously published result from our laboratory. Although repurposing statins for use in oncology is an attractive strategy, there are legitimate concerns about the potential for the drug to cause myopathy. Therefore, other pharmacological agents which inhibit the mevalonate pathway were evaluated to test the hypothesis that dual inhibition of the mevalonate pathway would synergistically cause ovarian cancer cell death. Bisphosphonates, such as zolendronic acid, are inhibitors of farnesyl diphosphate synthase. Zolendronic acid, and to lesser extends risedronate, potentiated the activity of pitavastatin in several assays assessing the growth and viability of ovarian cancer cells. In contrast, the geranylgeranyl transferase I inhibitor, GGTI-2133, antagonised the activity of pitavastatin. Similarly, knockdown of either GGTI-β or GGTII-β by RNAi failed to potentiate the activity of pitavastatin. However, combined knockdown of both geranylgeranyl transferases potentiated the activity of pitavastatin. To identify further drugs which could interact synergistically with pitavastatin, a library of 100 off-patent drugs was screened in combination with pitavastatin in cell growth assays. Several compounds were identified which potentiated the activity of pitavastatin and/or had notable activity as single agents. The most striking hit from this screen was prednisolone, a synthetic glucocorticoid. Subsequent studies confirmed the synergistic interaction between prednisolone and pitavastatin in several cell growth and viability assays. To evaluate the mechanism underlying this synergistic interaction, publically-available expression data were interrogated to identify mevalonate pathway enzymes whose expression was regulated by prednisolone. The effect of these candidate genes was then tested in ovarian cancer cells and levels of HMGCR, farnesyl diphosphate synthase and geranylgeranyl transferase II were found to be reduced. These data suggest that drug combinations inhibiting multiple points in the mevalonate pathway may increase the therapeutic window for pitavastatin and offer a potential treatment for ovarian cancer.
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