Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 79-95). Also available in print.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Not available / text

Coronary artery disease (CAD) is the most prevalent disorder and the leading cause of death worldwide. There are a number of CAD medications, which are effective and safe in most patients, but have been associated with adverse reactions such as angioedema induced by angiotensin I-converting enzyme inhibitors (AE-ACEi). In this study, we identified aminopeptidase P (APP) activity as an endophenotype for AE-ACEi, which is a heritable quantitative trait (heritability =0.336 +/- 0.251 SD) and is significantly reduced in a majority of our cases. Although initial mutation screening did not reveal any coding variants in XPNPEP2, which encodes membrane-bound APP, subsequent linkage analysis of APP activity in eight families provided a maximum LOD score (3.75) for this locus. Sequencing of additional cases identified a splice variant (314_431del) and a non-coding polymorphism (rs3788853) in this locus, which cosegregate with low plasma APP activity. The latter accounts for the linkage signal and is associated with AE-ACEi (P = 0.036). In addition, we identified other potential loci for APP activity and demonstrated that certain ACEi (Captopril and Enalapril) non-specifically inhibit APP activity. Furthermore, we detected polymorphisms associated with reduced APP and ACE activities among females with estrogen-dependent inherited angioedema. / We also conducted a genetic investigation of depression among CAD patients to identify common susceptibility loci which might explain the correlation between these diseases. Our candidate gene association study identified a polymorphism (rs216873) in the von Willebrand factor gene that was significantly associated (P = 7.4 x 10-5) with elevated depressive symptoms in our CAD cohort. These results suggest that risk factors for atherosclerosis also underlie susceptibility to depression among CAD patients. / This dissertation contributes to the field of genetics and pharmacogenomics of CAD. A better understanding of the toxic effects of CAD drugs will assist in the development of safer and more effective treatments. In addition, our results may facilitate clinical assays to identify individuals who are susceptible to angioedema prior to ACEi or estrogen therapy. Finally, our genetic investigation of depression in CAD patients reveals a novel drug target (VWF) for treatment of depression in cardiac cases.

The use of antibiotics and antimicrobial drugs has played a large role in the elimination of many infectious diseases, however the wide spread use of such drugs has given rise to the phenomenon of antimicrobial resistance and has rendered antibiotics ineffective to a broad range of bacteria. The aim of the study was to ascertain the differences if any in the phenotypic and genotypic resistance profiles of K. pneumoniae isolated from a single tertiary hospital in two surveillance studies undertaken at different times, viz., 2001 and 2007 with special emphasis on ESBLs. A correlation with antibiotic use was also undertaken. ESBL positives were identified and phenotypic resistance profiles were generated based on the resistance profiles of individual isolates by means of their MIC data. The molecular detection of ESBLs was carried out using representative isolates and sequencing was based on the phenotypic expression of the most common ESBL genes. The data was summarized using median values and interquartile ranges. Antibiotic use and susceptibility in 2000 was compared to that in 2007 using a Wilcoxon signed rank test for paired data since the same drugs were tested in both years. Of the isolates that were tested, sequencing revealed that TEM – 1 was identified in all isolates and SHV-1 and SHV-2 were identified in 60 % in the isolates collected in 2000 and 77 % and 11 % respectively in the isolates collected in 2007. SHV – 11 was present in 67% of isolates from 2007 and 55% of those were in combination with SHV – 1. Sequencing also revealed CTXM-15 present in one of the isolates collected in 2007. There was 100% susceptibility to cefoxitin and only one isolate in 2007 showing an intermediate result to imipenem. No novel β-lactamases were identified in this study; however the decrease in susceptibility over time is proof of bacterial evolution. The variety of β-lactamases and diversity of plasmid profiles in these two small populations provides proof to the claim that dissemination of resistance in Klebsiella pneumonia is effortless. Statistical analysis showed an increase in resistance from the year 2000 to 2007 however the correlation between overall antibiotic use and the increase in resistance did not reach statistical significance. It was observed that resistance increased despite only a slight increase in the use of a few antibiotics to which we attributed co-carriage of resistance genes. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Westville, 2012.

The lithiation of 3-sulfolene followed by subsequent treatment with an alkyl halide electrophile has been previously established as a method to produce 2-substituted-3-sulfolenes. Tandem reactivity with bis-alkyl halides has been observed to afford relatively simple bicyclic products. We hypothesized that it may be possible to access more complex bicyclic systems through use of bis-vinyl ketones as the electrophilic component. Herein, we present the outcome and mechanistic insights for the reaction between a variety of 3-sulfolene and substituted-3-sulfolene anions with bis-vinyl ketones to afford a variety of stereochemically complex fused, bridged and spiro bicyclic archetypes. The potential of these bicyclic-sulfone frameworks to act as molecular scaffolds for the generation of conformationally-restricted enzyme inhibitors is explored. Potent monocyclic small molecules that inhibit influenza’s neuraminidase enzyme have been developed as commercially successful antivirals. Similarly potent inhibitors against prokaryotic or eukaryotic neuraminidases have yet to be described. Selective inhibitors of these latter neuraminidase isozymes may provide useful treatments for bacterial infections (such as cholera and pneumonia) as well as a variety of cancers and metabolic disorders. A conformationally-restricted scaffold may prove ideal for designing selective (and potent) inhibitors against these underexplored enzymes. As a proof of principle, one of our rigid bicyclic-sulfone archetypes is elaborated to a drug-like scaffold that is shown to inhibit viral, bacterial and human neuraminidase enzymes. / Graduate / mgbrant@uvic.ca

[Truncated abstract] The development of several carbohydrate-based pharmaceuticals has stimulated an increased interest in the field of carbohydrate chemistry. The discovery of Acarbose and invention of Miglitol, treatments for type II diabetes, as well as the influenza treatments, Relenza and Tamiflu, have been largely responsible for this increased interest. These treatments operate by the inhibition of glycoside hydrolases, a group of enzymes important in a variety of biological processes. This thesis involves the study of a group of glycoside hydrolase inhibitors known as azasugars, which are nitrogen-containing sugar mimics . . . The final chapter, Chapter 4, focuses on the testing of these disaccharides as a possible alternative carbohydrate source for pre-term infants. Initially, commercially available glycoside hydrolases were used to detect any hydrolysis of the four disaccharides, with (206) exhibiting the most promising results (to provide D-glucose and D-galactose). Detailed kinetic studies were then conducted using homogenates obtained from pig intestinal mucosa. Unfortunately, the results indicated that (206) was unsuitable as an alternative carbohydrate source for pre-term infants.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2002. / Härtill 5 uppsatser.