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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.
51

Screening of natural products and alkylating agents for antineoplastic activity

Kanyanda Stonard Sofiel Elisa January 2007 (has links)
<p><b><font face="TimesNewRomanPS-BoldMT"> <p align="left">Apoptosis is a process in which a cell programmes its own death. It is a highly organized physiological mechanism in which injured or damaged cells are destroyed. Apart from physiological stimuli however, exogenous factors can induce apoptosis. Many anti-cancer drugs work by activating apoptosis in cancer cells. Natural substances have been found to have the ability to induce apoptosis in various tumour cells and these substances have been used as templates for the construction of novel lead compounds in anticancer treatment. On the other hand, alkylating agents such as cisplatin, cis- [PtCl2 (NH3) 2]have been widely used as antineoplastic agents for a wide variety of cancers including testicular, ovarian, neck and head cancers, amongst others. However, the use of cisplatin as an anticancer agent is limited due to toxicity and resistance problems. <font face="TimesNewRomanPSMT">The aim of this present study was to screen the leaves of </font><i><font face="TimesNewRomanPS-ItalicMT">Rhus laevigata</font><font face="TimesNewRomanPSMT">, a South African indigenous plant, for the presence of pro-apoptotic and anti-proliferative natural compounds and also to screen newly synthesised palladium based complexes (15 and 57) and a platinum based complex (58) for their antineoplastic activities tested against a panel of cell lines.</font></i></p> </font><font face="TimesNewRomanPS-BoldMT"> <p align="left">&nbsp / </p> </font></b></p>
52

Screening of natural products and alkylating agents for antineoplastic activity

Kanyanda Stonard Sofiel Elisa January 2007 (has links)
<p><b><font face="TimesNewRomanPS-BoldMT"> <p align="left">Apoptosis is a process in which a cell programmes its own death. It is a highly organized physiological mechanism in which injured or damaged cells are destroyed. Apart from physiological stimuli however, exogenous factors can induce apoptosis. Many anti-cancer drugs work by activating apoptosis in cancer cells. Natural substances have been found to have the ability to induce apoptosis in various tumour cells and these substances have been used as templates for the construction of novel lead compounds in anticancer treatment. On the other hand, alkylating agents such as cisplatin, cis- [PtCl2 (NH3) 2]have been widely used as antineoplastic agents for a wide variety of cancers including testicular, ovarian, neck and head cancers, amongst others. However, the use of cisplatin as an anticancer agent is limited due to toxicity and resistance problems. <font face="TimesNewRomanPSMT">The aim of this present study was to screen the leaves of </font><i><font face="TimesNewRomanPS-ItalicMT">Rhus laevigata</font><font face="TimesNewRomanPSMT">, a South African indigenous plant, for the presence of pro-apoptotic and anti-proliferative natural compounds and also to screen newly synthesised palladium based complexes (15 and 57) and a platinum based complex (58) for their antineoplastic activities tested against a panel of cell lines.</font></i></p> </font><font face="TimesNewRomanPS-BoldMT"> <p align="left">&nbsp / </p> </font></b></p>
53

A study of county extension agents' program planning role in North Carolina, Ohio and Virginia

Farnsworth, William Franklin, January 1963 (has links)
Thesis (Ph. D.)--University of Wisconsin, 1963. / Extension Repository Collection. Typescript (carbon copy). Includes autobiographical sketch of author. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 205-209).
54

Synthesis and characterization of novel [Pt(diimine) (acylthiourea)]+ complexes as potential anticancer agents and exploring the use of sulphobutyl-ether-B-cyclodextrin and surfactant micelles as a drug delivery system

Magwaza, Rachael Ntombikayise January 2017 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirement for the degree Master of Science (MSc) in Chemistry. Johannesburg, March 2017. / A series of [Pt(diimine)(Ln-O,S)]Cl complexes, where Ln-O,S represents a series of N,N dialkyl-N’-acylthiourea ligands and diimine represents (1,10-Phenanthroline; 5,6-dimethyl 1,10-phenanthroline or [3,2-d:2’,3’-f]-quinoxaline were successfully synthesised and characterised. A new crystal structure was obtained for N,N-di(2-hydroxy)-N’ benzoylthiourea which revealed an interesting herringbone crystal packing arrangement. The cytotoxicity of the series of complexes was evaluated on H1975 lung cancer cell lines at 50 µM and 5 µM. All the complexes were highly cytotoxic with cell death of 90-98% at 50 µM. However, at 5 µM there were much more variations on cell viability percentages. Although the structure–activity relationship can only be established when the IC50 (the concentration of an inhibitor where the response is reduced by half) values are determined, it is clear that the complexes containing the methyl substituents on the 5 and 6 positions of the phenanthroline moiety were the most cytotoxic with almost 98% cell death at 5 µM. The solubility of the complexes did improve by using N,N-dialkyl-N’-acylthiourea as ancillary ligands, however aqueous solubility remains a major problem. Sulphobutyl-ether-β-cyclodextrin (captisol) and low-molecular-weight surfactant micelles as drug delivery systems were considered in attempt to improve the solubility. DOSY NMR Spectroscopy revealed that there was no inclusion complex formation between the complex and capstiol, although the chemical shift trend suggested that there is at least some interaction. The low-molecular-weight surfactant micelles were considered as an alternative, which showed some promise as a drug delivery system, since the aqueous solubility improved and a colloidal suspension was obtained. / LG2018
55

Study on the in vitro anti-tumor effect of Acanthopanax senticosus.

January 2008 (has links)
Wan, Chung Tin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 126-139). / Abstracts in English and Chinese. / Thesis / Assessment Committee --- p.i / Acknowledgement --- p.ii / Abstract (English) --- p.iii / Abstract (Chinese) --- p.v / List of Abbreviations --- p.vii / List of Tables --- p.ix / List of Figures --- p.x / Chapter Chanter 1 --- Introduction / Chapter 1.1. --- Overview of cancer --- p.1 / Chapter 1.1.1 --- Breast cancer --- p.1 / Chapter 1.1.2 --- Hepatocellular carcinoma (HCC) --- p.2 / Chapter 1.2. --- Role of natural products in the fight against cancer --- p.3 / Chapter 1.2.1 --- Introduction of Astragalus membranaceus --- p.4 / Chapter 1.2.2 --- Introduction of Acanthopanax senticosus --- p.9 / Chapter 1.2.3 --- Introduction of Grifola Frondosa --- p.13 / Chapter 1.3. --- Apoptosis and cancer --- p.17 / Chapter 1.3.1 --- Caspases --- p.20 / Chapter 1.3.2 --- Intrinsic apoptotic pathway --- p.21 / Chapter 1.3.3 --- Extrinsic apoptotic pathway --- p.23 / Chapter 1.3.4 --- Execution of apoptosis --- p.26 / Chapter 1.4 --- Cell cycle and cancer --- p.27 / Chapter 1.5 --- Objective of this project: --- p.29 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Materials: --- p.30 / Chapter 2.1.1 --- Culture medium --- p.30 / Chapter 2.1.2 --- Buffers and reagents --- p.31 / Chapter 2.1.3 --- Herbs --- p.34 / Chapter 2.2 --- Methods --- p.35 / Chapter 2.2.1 --- Cell cultures --- p.35 / Chapter 2.2.1.1 --- Cell lines --- p.35 / Chapter 2.2.1.2 --- Cell culture techniques --- p.36 / Chapter 2.2.1.3 --- Cryopreservation of cell lines --- p.36 / Chapter 2.2.2 --- Proliferation assay --- p.37 / Chapter 2.2.2.1 --- MTT assay --- p.37 / Chapter 2.2.2.2 --- Isolation of PBMC --- p.38 / Chapter 2.2.2.3 --- XTT --- p.39 / Chapter 2.2.3 --- DNA fragmentation --- p.39 / Chapter 2.2.4 --- Flow cytometry --- p.41 / Chapter 2.2.4.1 --- Detection of mitochondrial membrane depolarization by the use of JC-1 --- p.41 / Chapter 2.2.4.2 --- Annexin-V-FITC PI labeling of apoptotic cells --- p.42 / Chapter 2.2.4.3 --- Cell cycle analysis --- p.43 / Chapter 2.2.5 --- Western blotting --- p.43 / Chapter 2.2.5.1 --- Total protein extraction --- p.44 / Chapter 2.2.5.2 --- Determining protein concentration --- p.44 / Chapter 2.2.5.3 --- SDS-PAGE --- p.45 / Chapter 2.2.5.4 --- Electroblotting --- p.45 / Chapter 2.2.5.5 --- Probing --- p.46 / Chapter 2.2.5.6 --- ECL --- p.46 / Chapter 2.2.6 --- Preparation of herbal extracts --- p.47 / Chapter 2.2.6.1 --- Preparation of extract of Astragalus membranaceus and Grifola frondosa --- p.47 / Chapter 2.2.6.2 --- Preparation of Acanthopanax senticosus aqueous extract --- p.47 / Chapter 2.2.6.3 --- Partition of Acanthopanax --- p.47 / Chapter 2.2.6.4 --- Column purification of ethyl-acetate fraction --- p.48 / Chapter 2.2.6.5 --- Analytical thin layer chromatography --- p.49 / Chapter 2.2.7 --- Statistical Analysis --- p.50 / Chapter Chanter 3 --- Results / Chapter 3.1 --- Extractions --- p.51 / Chapter 3.2 --- Anti-proliferative effect of herbal extracts on cancer cell lines --- p.51 / Chapter 3.3 --- Partition of Acanthopanax methanol extract --- p.56 / Chapter 3.4 --- Anti-proliferative effect of Acanthopanax partition fractions on breast cancer cells --- p.59 / Chapter 3.5 --- Column chromatography of ethyl acetate fraction --- p.59 / Chapter 3.6 --- Anti-proliferative effect of various sub-fractions on breast cancer cells --- p.64 / Chapter 3.7 --- Effect of sub-fractions on PBMC proliferation --- p.76 / Chapter 3.8 --- Kinetic study of anti-proliferative effect of Fc --- p.76 / Chapter 3.9 --- Flow cytometric analysis --- p.79 / Chapter 3.91 --- JC-1 staining --- p.79 / Chapter 3.92 --- Annexin-P1 labeling --- p.79 / Chapter 3.93 --- Cell cycle analysis --- p.80 / Chapter 3.10 --- DNA fragmentation assay --- p.88 / Chapter 3.11 --- Western blotting --- p.91 / Chapter Chanter 4 --- Discussion --- p.99 / Chapter Chapter 5 --- Conclusion --- p.124 / References --- p.126
56

Synthetic studies n bioactive natural products. Part I, An approach towards the nootrophic agent huperzine A. Part II, Synthesis of the tricarbonyl subunit of rapamycin

Jeffrey, Scott C. 04 April 1996 (has links)
Graduation date: 1996
57

Investigations into the chemical mechanisms of biological activity by heterocyclic di-N-oxides and 1,2 benzodithiolan-3-one 1-oxides /

Ganley, Brian Christopher, January 2000 (has links)
Thesis (Ph. D.)--University of Missouri--Columbia, 2000. / "December 2000." Typescript. Vita. Includes bibliographical references. Also available on the Internet.
58

Transactional agents : towards a robust multi-agent system /

Nagi, Khaled. January 1900 (has links)
Thesis (Ph.D) - University of Karlsruhe, 2001. / Includes bibliographical references and index. Also available via the World Wide Web.
59

The relationship between job satisfaction and locus of control amongst call centre representatives in a call centre in Durban, KwaZulu-Natal /

Chetty, Pamela Jaskiaya Jeannette. January 2008 (has links)
Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2008. / Full text also available online. Scroll down for electronic link.
60

Design and biological evaluation of novel antitumor agents with mechanisms of action against topoisomerase II and/or G-quadruplexes

Kim, Mu-yong 28 August 2008 (has links)
Not available / text

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