published_or_final_version / Surgery / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Surgery / Master / Master of Philosophy

published_or_final_version / Biological Sciences / Master / Master of Philosophy

published_or_final_version / Pathology / Doctoral / Doctor of Philosophy

published_or_final_version / Surgery / Master / Master of Philosophy

published_or_final_version / Surgery / Doctoral / Doctor of Philosophy

Master of Science / Department of Electrical and Computer Engineering / Punit Prakash / Microwave ablation is a minimally invasive therapeutic modality used for the treatment of cancer in various organs. In this procedure, microwave energy is sent through a thin antenna placed inside the tumor. The microwave energy radiated from the antenna generates heat which kills the tumor cells by necrosis. During multiple-applicator microwave ablation, geometric estimates of treatment outcome are typically obtained by assuming parallel insertion of the applicators. This assumption is based on the guidelines provided in the brochures of antenna manufacturing companies. This assumption is flawed because it is rare to insert the antennas in parallel configuration due to the flexible nature of the antennas and the presence of intervening organs. Furthermore, movement of patients during the treatment procedure alters the position of the antennas. In order to see the effect of non-parallel insertion of antennas, model-based treatment planning may be instructive. Treatment planning can also determine the changes needed to be made for prospective ablation therapy if the antennas are not positioned in their ideal parallel configuration. This thesis provides a detailed computational comparison of the skewed configurations of microwave antennas to their closest parallel configurations. The metric used for com-paring the similarity between the cases is Dice Similarity Coefficient (DSC). Experimental results to validate the computational data are also discussed. Computations were done by using realistic cases of antenna positions obtained from Rhode Island Hospital.

Ph.D. thesis, Faculty of Health Sciences, University of the Witwatersrand, 2009

Thesis is submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Science (Biochemistry), University of the Witwatersrand, Johannesburg, 1992 / An investigation has been made into aspects of the expression of oncogenes in normally dividing cells and in hepatoceilular carcinoma (Hee). HOC occurs commonly in Southern Africs, and thf1aetiology ·ofthis tumour lsaseccieted with hepatitis a virus (HBV) infection. c·erbA, c..mva and e-tos but not c~Ha..res mANA were elevatad in tumours and adjacent hepatic tissue from the same petiEJ;htswhen compared to normal liver. Amounts of Fos and MYQ prot~in in the liver tumour specimens were else raised. The"e was some correlation between the patients' serum a..fetoproteirt concentretlons, histological features of tumour differentiatic)t"l, c..mvc and c40s r.ixpression. expression of e-tas and c..myc has been reportec to be elevated after stimulation of cells to alvlde, ,'1$ occurs during liver r19ganeration. This was corroborated by the findin~ that c-mvc, c·fo~· and c-jun mRNA concentratlona "Jere increased it"! cultured 3T6 mouse fibroblasts following treatment with alkaline medium aa a mitogenlo stimulus. The time course of the expression of these oncogenes was similar to that reported after gro\l'l/th factor sttmulation, The H[~V X..gene ma\' be responsible for increased oncogene expression it' YCC as a result of its documented trans activating properties. This vi!'a~ gene is unusual in that it has a codon preferanc";which is similar to that of eukarvotic ceU genes. Also HBV may ha'V& evolved from ti similar ancestral virus to that giving rise to retroviruses. These ideas suggest that the HBV X·gene is a viral oncogene derived from a host homologue. Low stringency Northern brot hybridisation using a X-gene probe denlonstrated a murine transcrlpt in heart and thymus. Attempts to isolate the sequence from mouse heart and thymus eDNA libraries ware unsuccessful despite ext,~n$jve screening with sensitive probes (SP6 palymerfjsa and peR fab(':.lUed X~gen~~fragments). Conserved X~gene \ . I sequences were also used fot the desigr:Jof primers in .~.peR bas£'d method " . II aimed at isolating a mammalian sequence. No sinnificant sequsnce \\ homology was found bet\lveen the HBVI\X..gene and Ol\A ampllfle'd from \1 l! gen(llmic and eDNA I1br'srytemplate sou~\pes.The peR preducts ttppeared to have been artef.,ots of arnplWaation. ~~n'IJreto detect the hQrtll.)logous gene may have resu~ted from poo' complS,JIlentarity between the VIral ant! \\ mammalian secuencec, 1\ \\ Non..~pecific amplification is commonly enct~unter&d when u$1110 PCli'. A qtJick asvmmatrlc re·ampW~catj(ii1 method I,?ssed on eXUOSilin of an " interm.uly' hybrfdising X·gelllapfimar we! davisQ\j to confirm FICRprOdu(,ts. The l"n1ithodwas specific irlthat "ver~ single bas~ mlsmatohe$ betwsen the internal primer and tem1>late re;.,ultad in fatJut~ of dete(;tabla \tUim$f extension. / GR 2016

Ong Chik Ying Rose. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 181-195). / Abstracts in English and Chinese. / Acknoledgements --- p.i / List of Abbreviations --- p.ii / Abstract --- p.iii / Abstract in Chinese --- p.v / List of Publications and Abstracts --- p.vii / List of Figures --- p.viii / List of Tables --- p.xi / Contents --- p.xii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Saponins --- p.3 / Chapter 1.1.1 --- Structure of saponins --- p.3 / Chapter 1.1.2 --- Occurrence of saponins --- p.7 / Chapter 1.1.3 --- Bioactivities of saponins --- p.8 / Chapter 1.2 --- Paris Polyphylla --- p.9 / Chapter 1.2.1 --- Chonglou --- p.11 / Chapter 1.3 --- Polyphyllin D --- p.12 / Chapter 1.4 --- Apoptosis --- p.15 / Chapter 1.4.1 --- Apoptosis and necrosis --- p.16 / Chapter 1.4.2 --- Initiation phase of apoptosis --- p.16 / Chapter 1.4.2.1 --- Extrinsic apoptotic pathway --- p.18 / Chapter 1.4.2.2 --- Intrinsic apoptotic pathway --- p.19 / Chapter 1.4.3 --- Execution phase of apoptosis --- p.19 / Chapter 1.4.4 --- Termination phase of apoptosis --- p.20 / Chapter 1.5 --- Multi-drug resistance (MDR) --- p.21 / Chapter 1.5.1 --- MDR mediated by decreased drug accumulation --- p.21 / Chapter 1.5.2 --- MDR mediated by enhanced anti-oxidant enzyme activities --- p.25 / Chapter 1.5.3 --- MDR mediated by enhanced detoxification of drugs --- p.25 / Chapter 1.5.4 --- MDR mediated by enhanced DNA repair system --- p.26 / Chapter 1.5.5 --- MDR mediated by altered apoptotic pathway --- p.26 / Chapter 1.5.6 --- Current strategies for overcoming multidrug resistance in cancer --- p.27 / Chapter 1.6 --- Hepatocellular carcinoma (HCC) --- p.30 / Chapter 1.7 --- Objectives of project --- p.32 / Chapter Chapter 2 --- Materials and Methods --- p.33 / Chapter 2.1 --- Materials --- p.34 / Chapter 2.1.1 --- Culture of Cells --- p.34 / Chapter 2.1.1.1 --- Cell lines --- p.34 / Chapter 2.1.1.2 --- Preservation of Cells --- p.35 / Chapter 2.1.2 --- Culture Media --- p.36 / Chapter 2.1.2.1 --- RPMI 1640 (Phenol Red Medium) --- p.36 / Chapter 2.1.2.2 --- RPMI 1640 (Phenol Red-free Medium) --- p.36 / Chapter 2.1.3 --- Buffers and Reagents --- p.37 / Chapter 2.1.3.1 --- Buffer for Common Use --- p.37 / Chapter 2.1.3.2 --- Reagents for Annexin-V-FITC/PI Assay --- p.37 / Chapter 2.1.3.3 --- Reagents for Western Blotting Analysis --- p.37 / Chapter 2.1.4 --- Chemicals --- p.40 / Chapter 2.1.4.1 --- Fluorescence Dyes --- p.40 / Chapter 2.1.4.2 --- Antibodies --- p.41 / Chapter 2.1.4.3 --- Other Chemicals --- p.42 / Chapter 2.1.5 --- Summary of chemicals used in this study --- p.43 / Chapter 2.2 --- Methods --- p.48 / Chapter 2.2.1 --- In vitro Cell Cytotoxicity Assay --- p.48 / Chapter 2.2.1.1 --- AlamarBlue Assay --- p.48 / Chapter 2.2.2 --- Flow Cytometry --- p.50 / Chapter 2.2.2.1 --- Analysis by Flow Cytometry --- p.50 / Chapter 2.2.2.2 --- Determination of Apoptotic and Late Apoptotic/Necrotic Cells with Annexin-V-FITC/PI Cytometric Analysis --- p.50 / Chapter 2.2.2.3 --- Determination of Mitochondrial Membrane Potential in cells --- p.51 / Chapter 2.2.2.4 --- Determination of Hydrogen Peroxide (H2O2) Release in cells --- p.52 / Chapter 2.2.2.5 --- Measurement of doxorubicin accumulation in cells --- p.53 / Chapter 2.2.2.6 --- Determination of P-glycoprotein expression level in cells --- p.54 / Chapter 2.2.2.7 --- Determination of mitochondrial depolarization and swellingin isolated mitochondria --- p.54 / Chapter 2.2.3 --- Methods involved in DNA sequencing of MDRl promoter --- p.56 / Chapter 2.2.3.1 --- DNA extraction --- p.56 / Chapter 2.2.3.2 --- DNA and Gel Band Purification --- p.56 / Chapter 2.2.3.3 --- Assessment of DNA amount --- p.57 / Chapter 2.2.3.4 --- Polymerase Chain Reaction --- p.57 / Chapter 2.2.3.5 --- Agarose Gel Electrophoresis --- p.59 / Chapter 2.2.3.6 --- Preparation for DNA sequencing --- p.59 / Chapter 2.2.4 --- Western Blotting Analysis --- p.61 / Chapter 2.2.4.1 --- Preparation of Proteins from Cells --- p.61 / Chapter 2.2.4.2 --- Preparation of proteins from isolated mitochondria --- p.63 / Chapter 2.2.4.3 --- Protein analysis with Western analysis --- p.63 / Chapter 2.2.5 --- Confocal laser scanning microscopy (Confocal microscopy) --- p.66 / Chapter 2.2.5.1 --- Analysis with confocal microscopy --- p.66 / Chapter 2.2.5.2 --- Determination of mitochondrial changes in cells by confocal microscopy --- p.66 / Chapter 2.2.5.3 --- Determination of lysosomal rupture in cells by confocal microscopy --- p.67 / Chapter 2.2.6 --- Mitochondrial isolation --- p.68 / Chapter Chapter 3 --- Results 一 Resistance Mechanisms in RHepG2 cells --- p.69 / Chapter 3.1 --- Resistance of RHepG2 cells towards various chemical agents --- p.70 / Chapter 3.1.1 --- RHepG2 cells are resistant to doxorubicin --- p.70 / Chapter 3.1.2 --- RHepG2 cells are resistant to taxol --- p.72 / Chapter 3.1.3 --- RHepG2 cells are resistant to valinomycin --- p.74 / Chapter 3.2 --- Resistance mechanism in RHepG2 cells --- p.76 / Chapter 3.2.1 --- Reduced doxorubicin accumulation is observed in RHepG2 cells --- p.76 / Chapter 3.2.2 --- More P-glycoproteins on the cell surface was observed in RHepG2 cells --- p.80 / Chapter 3.2.3 --- Inhibition of P-glycoprotein activity increased doxorubicin accumulation in RHepG2 cells --- p.82 / Chapter 3.2.4 --- HepG2 and RHepG2 cells contain the same P-glycoprotein promoter region --- p.86 / Chapter 3.2.5 --- RHepG2 over-expressed Bcl-2 --- p.91 / Chapter 3.2.6 --- HepG2 and RHepG2 cells had the same level of Bax protein --- p.93 / Chapter Chapter 4 --- Results - Effects of Polyphyllin D in HepG2 and RHepG2 cells --- p.95 / Chapter 4.1 --- Cytotoxicity of Polyphyllin D in HepG2 and RHepG2 cells --- p.96 / Chapter 4.1.1 --- Polyphyllin D exhibited cytotoxic effect in both HepG2 and RHepG2 cells --- p.96 / Chapter 4.2 --- Apoptotic mechanism caused by Polyphyllin D in HepG2 and RHepG2 cells --- p.93 / Chapter 4.2.1 --- Polyphyllin D caused apoptosis in HepG2 and RHepG2 cells --- p.98 / Chapter 4.2.2 --- Polyphyllin D did not activate caspase8 --- p.103 / Chapter 4.2.3 --- Polyphyllin D did not concentrate on the plasma membrane of cells --- p.106 / Chapter 4.2.4 --- Polyphyllin D did not change Bcl-2 level in HepG2 and RHepG2 cells --- p.109 / Chapter 4.2.5 --- Polyphyllin D treatment enhanced Bax protein expression in both HepG2 and RHepG2 cells --- p.111 / Chapter 4.2.6 --- Polyphyllin D caused cytochrome c and AIF release in HepG2 and RHepG2 cells --- p.113 / Chapter 4.2.7 --- Polyphyllin D induced mitochondrial membrane depolarization in HepG2 and RHepG2 cells --- p.118 / Chapter 4.2.8 --- Polyphyllin D caused mitochondrial swelling in HepG2 and clustering of mitochondriain RHepG2 cells --- p.122 / Chapter 4.2.9 --- "Polyphyllin D caused H202 release in HepG2 and RHepG2 cells, and the cytotoxic effects of Polyphyllin D could be reduced by NAC" --- p.127 / Chapter 4.2.10 --- Polyphyllin D caused permeabilization of lysosomes --- p.132 / Chapter 4.3 --- Site of action of Polyphyllin D in cells --- p.135 / Chapter 4.3.1 --- Purity of isolated mitochondria --- p.135 / Chapter 4.3.2 --- Polyphyllin D caused cytochrome c release from the HepG2 and RHepG2 isolated mitochondria --- p.137 / Chapter 4.3.3 --- Polyphyllin D induced mitochondrial depolarization in HepG2 and RHepG2 isolated mitochondria --- p.139 / Chapter 4.3.4 --- Polyphyllin D caused mitochondrial swelling in HepG2 and RHepG2 isolated mitochondria --- p.142 / Chapter 4.4 --- Resistance reversal effects of Polyphyllin D in RHepG2 cells --- p.144 / Chapter 4.4.1 --- Polyphyllin D increased doxorubicin accumulation in RHepG2 cells --- p.144 / Chapter 4.4.2 --- P-glycoprotein expression was not down-regulated after Polyphyllin D treatment --- p.146 / Chapter 4.4.3 --- Co-treatment of doxorubicin with Polyphyllin D had enhanced cytotoxic effect --- p.148 / Chapter Chapter 5 --- Discussion - Resistance mechanisms in RHepG2 cells --- p.150 / Chapter 5.1 --- Resistance of RHepG2 cells towards various chemical reagents --- p.151 / Chapter 5.2 --- Resistance mechanisms in RHepG2 cells --- p.154 / Chapter Chapter 6 --- Discussion - Effects of Polyphyllin D in HepG2and RHepG2 cells --- p.159 / Chapter 6.1 --- Cytotoxicity of Polyphyllin D in HepG2 and RHepG2 cells --- p.160 / Chapter 6.2 --- Apoptotic mechanisms caused by Polyphyllin D in HepG2 and RHepG2 cells --- p.162 / Chapter 6.3 --- Site of action of Polyphyllin D in HepG2 andRHepG2 cells --- p.172 / Chapter 6.4 --- Resistance reversal effects of Polyphyllin D in RHepG2 cells --- p.175 / Chapter Chapter 7 --- Future Perspectives --- p.177 / Chapter Chapter 8 --- Conclusion --- p.179 / References