Call number: LD2668 .T4 1952 G71 / Master of Science

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

In the past 15-20 years, advances in antibody engineering have facilitated the generation and isolation of monoclonal antibodies (mAbs) to a wide array of antigens. Consequently, mAbs have become essential therapeutic tools and currently dominate the global protein therapeutics market. The engineering of anti-infective antibodies, however, has proven quite a challenge, despite the fact that antibodies were naturally evolved to fight infections. The identification of suitable antigens, the mode of administration and the high cost associated with the production of antibody therapeutics are some of the major hurdles for the progress of anti-infective antibodies. This dissertation addresses issues concerning the development of anti-infective antibodies against two different pathogens: SARS coronavirus (CoV) and two pathogenic species of Burkholderia bacteria. To investigate the role of affinity in viral neutralization and evolution of escape mutants, we first sought to isolate an antibody with high affinity towards the receptor binding domain (RBD) of SARS-CoV. Following high-throughput screening of a library of random mutants via the APEx display system, we isolated antibodies with affinities in the range of 0.8 nM - 0.1 nM. The affinity was further improved by additional mutagenesis and DNA shuffling, and a high affinity variant (45pM) with ~300-fold improvement over the parental antibody was isolated. Evaluation of these antibodies in an in vitro assay demonstrated that neutralization of wild-type Urbani strain of SARS-CoV correlates well with the affinity of the antibody, with higher affinity leading to greater neutralization. Moreover, the antibody exhibiting the highest affinity could neutralize SARS-CoV escape mutants that evaded neutralization by both parental and lower affinity antibodies. Another important aspect for the development of anti-infective antibodies concerns the identification of suitable antigen targets to be used in the isolation of antibodies. In an effort to develop a high-throughput screening method for the isolation of antibodies to a wide array of antigens, we used a synthetic antibody (Fab) library constructed by a minimalist approach and displayed on the surface of filamentous bacteriophage. The library was screened against antigens from Burkholderia pseudomallei and Burkholderia mallei. After only three rounds of selection and enrichment against five different antigens, we obtained Fabs specific to four of the antigens as confirmed by ELISA. These results not only demonstrate the use of a synthetic antibody library for the isolation of antibodies against infectious pathogens, but also its feasibility, and potential applicability as a high-throughput screen for a variety of antigens. / text

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg. in partial fulfilment of the requirements for the degree of Master of Science in Medicine ( Pharmaceutical Affairs ) / The Retuceae is an aromatic family of plants confined to the Fynbos biome in South Africa. This family is represented by a number of genera e.g. Agasthosma, Adenandra, Coleonema, Vepris etc. all containing a number of species which have been used for centuries in traditional healing. Although many of these species have been used for centuries in local healing rites the biological activity and phytochemistry are poorly recorded. / IT2018

A research report submitted to the faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Medicine ( Pharmaceutical Affairs ) / This project was conducted to investigate properties and to record the essential oil profiles of a selection of species belonging to the genus agasthosma. Plants have been used for many years by the local South African to treat various infections and illnesses. This knowledge has largely been untapped. Buchu is one of the plant species that are used extensively by the San and Khoi people. It is remarkable that of the ca. 150 agathosma species indigenous to South Africa only two species ( Agasthosma crenulata and agathosma betulina ) have been investigated for biological activity. The genus Agasthosma is traditionally used for the following conditions ; stomach ailments, fever, coughs, cold, flu, urinary tract, and kidney infections, haematuria, prostatitis, rheumatism, gout, bruises and for antiseptic purposes. / IT2018

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master in Science ( Medicine ) Pharmaceutical Affairs / Lippia javanica is a widely spread woody shrub and the major traditional use is reflected in its vernacular name; fever tea ' koorsbossie '. An infusion of the leaves is also used as a decongestant for colds and coughs. Infusions may also be used topically to treat scabies and lice A preliminary study indicated that the essential oil chemistry varies dramatically both within and between natural plant populations. / IT2018

A RESEARCH REPORT SUBMITTED TO THE FACULTY OF HEALTH SCIENCES, UNIVERSITY OF WITWATERSRAND, JOHANNESBURG, IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF PHARMACY IN CLINICAL PHARMACY 2004 / The purpose of the study was to evaluate the use of cefotaxime with the idea of improving its use within the hospital. Improving the use of cefotaxime could result in a change in the proportion spent from the pharmacy budget. More importantly a change in prescribing patterns of this drug could also result in a reduction in resistant patterns of cefotaxime. / IT2018

A thesis submitted to the Cape Peninsula University of Technology in fulfilment of the requirements for the MASTERS DEGREE IN TECHNOLOGY (CHEMISTRY) Department of Chemistry January 2007 / An increasing number of natural products possessing the oleanolic acid moiety have been shown to demonstrate a wide spectrum of biological activity. This thesis deals with the extraction and isolation of oleanolic acid from Syzigium aromaticum and the examination of its stereochemistry and crystal structure by X-ray diffraction. The synthetic routes used for converting functional groups on the oleanolic acid molecule to afford derivatives are described in Chapter 5. Oleanolic acid and its derivatives were evaluated for antimicrobial activity. Three different procedures viz. Kirby-Bauer, Broth dilution and Tetrazolium salt chemosensitivity were used. Acceptable results were obtained from the last method and these were used to arrive at conclusions regarding this study.

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2007 / An increasing number of natural products possessing the oleanolic acid moiety have been shown to demonstrate a wide spectrum of biological activity. This thesis deals with the extraction and isolation of oleanolic acid from Syzigium aromaticum and the examination of its stereochemistry and crystal structure by X-ray diffraction. The synthetic routes used for converting functional groups on the oleanolic acid molecule to afford derivatives are described in Chapter 5. Oleanolic acid and its derivatives were evaluated for antimicrobial activity. Three different procedures viz. Kirby-Bauer, Broth dilution and Tetrazolium salt chemosensitivity were used. Acceptable results were obtained from the last method and these were used to arrive at conclusions regarding this study.

Typescript (photocopy) / 199 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--Dept. of Medicine, University of Adelaide, 1981