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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.
381

Anticarcinogenic effects of genistein and anthocyanin extract in MCF-7 human breast cancer cells

Unknown Date (has links)
This study investigated potential apoptotic and anti-proliferative effects of the phytochemicals, genistein and anthocyanin extract, as single and combined treatments in MCF-7 human breast cancer cells. Cells were exposed to single and combined treatments with the phytochemiclas for 48 and 72 hours. Cell viability was assessed using the MTT bioassay. Apoptosis induction was assessed using acridine orange ethidium bromide and rhodamine 123 ethidium bromide fluorescence assays. Both singe and combination treatments induced dose- and time-dependent apoptotic cell death in MCF-7 cells. The percentage of apoptosis was higher in combination treatments than single treatments with either phytochemical, although the difference was not statistically significant. The combination of genistein and anthocyanin extract peaked in efficacy at 48 hours of treatment, to exhibit significantly greater (P<. O5) dose- and time-dependent cell cytotoxicity than single treatments. This study reveals potential chemopreventive implications for the complementary effects of genistein and anthocyanin extract. / by Corine M. Stinson. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
382

Empirical beam angle optimization for lung cancer intensity modulated radiation therapy

Unknown Date (has links)
Empirical methods of beam angle optimization (BAO) are tested against the BAO that is currently employed in Eclipse treatment planning software. Creating an improved BAO can decrease the amount of time a dosimetrist spends on making a treatment plan, improve the treatment quality and enhance the tools an inexperienced dosimetrist can use to develop planning techniques. Using empirical data created by experienced dosimetrists from 69 patients treated for lung cancer, the most frequently used gantry angles were applied to four different regions in each lung to gather an optimal set of fields that could be used to treat future lung cancer patients. This method, given the moniker FAU BAO, is compared in 7 plans created with the Eclipse BAO choosing 5 fields and 9 fields. The results show that the conformality index improved by 30% or 3% when using the 5 and 9 fields. The conformation number was better by 12% from the 5 fields and 9% from the 9 fields. The organs at risk (OAR) were overall more protected to produce fewer nonstochastic effects from the radiation treatment with the FAU BAO. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
383

A Feminist Cultural Study of Identity, Hair Loss, and Chemotherapy

Unknown Date (has links)
The main aim of this dissertation is to discuss the way women negotiate the cultural meaning of hair loss, alopecia, as a result of undergoing chemotherapy, and to understand, accordingly, how cancer's cultural effects regarding women can be deeply different from those of men. Very few studies have been done about the cultural impact and resonance of alopecia. It is often regarded as "secondary" to other effects of chemotherapy. Because, in many cultures, head hair for women expresses or manifests attractiveness and power, to be bald is to be deprived of the ability to fit into society, whether in the public or private sphere. The study examines the representation of such women in the media, audience/subject responses to these representations, and interrogates women's identities and representations in terms of Laura Mulvey's theory of the male gaze. Women who have experienced chemotherapy-induced alopec ia were interviewed in this regard. Other contributive feminist, cultural and/or media studies works, such as those by Suzanna Walters, Susan Bordo, Naomi Wolf, Donna Haraway, Stuart Hall, Kimberle Crenshaw, and Judith Butler, help facilitate the analysis. From these perspectives, a historical analysis takes into consideration the symbolic dimension of hair, especially women's head hair, within Western cultural history, particularly in France and a multicultural America. In addition, a textual analysis looks at women, cancer, and hair loss as represented in popular culture characters and personalities. The study insists on the necessity for women to resist to the culture industries and deconstruct the male gaze, as well as the female gaze, which can both contribute to, and perpetuate women's objectification. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection
384

Comparison of treatment plans calculated using ray tracing and Monte Carlo algorithms for lung cancer patients having undergone radiotherapy with cyberknife

Unknown Date (has links)
The purpose of this research is to determine the feasibility of introducing the Monte Carlo (MC) dose calculation algorithm into the clinical practice. Unlike the Ray Tracing (RT) algorithm, the MC algorithm is not affected by the tissue inhomogeneities, which are significant inside the chest cavity. A retrospective study was completed for 102 plans calculated using both the RT and MC algorithms. The D95 of the PTV was 26% lower for the MC calculation. The first parameter of conformality, as defined as the ratio of the Prescription Isodose Volume to the PTV Volume was on average 1.27 for RT and 0.67 for MC. The results confirm that the RT algorithm significantly overestimates the dosages delivered confirming previous analyses. Correlations indicate that these overestimates are largest for small PTV and/or when the ratio of the volume of lung tissue to the PTV approaches 1. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
385

The importance of immobilization and localization of gynecological applicators in high dose rate brachytherapy treatments

Unknown Date (has links)
Intracavitary high dose rate (HDR) brachytherapy is a form of radiation therapy generally in which a post-surgical tissue margin is treated. The dose gradient of HDR brachytherapy is very steep, and thus small displacements of the applicator, even as small as 1 mm, could potentially cause significant variations of dose which could result in undesired side effects such as overdose of a critical organ. In this retrospective dosimetric study, the variation of dose due to various small range motions of gynecological applicators is investigated. The results show that the implementation of additional immobilization and localization devices along with other safety measures needs to be further investigated. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection
386

Polyphyllin D activates mitochondrial and lysosomal apoptotic pathway in drug resistant RHepG2 cells. / 甾體皂甙激活含多藥耐藥性肝癌細胞RHepG2之線粒體與溶體細胞凋亡途徑 / CUHK electronic theses & dissertations collection / Zi ti zao dai ji huo han duo yao nai yao xing gan ai xi bao RHepG2 zhi xian li ti yu rong ti xi bao diao wang tu jing

January 2007 (has links)
By using the acridine orange (AO) staining method to examine the release of contents from lysosomes, it was found that PD released AO into the cytosol in both cell lines. However, the releasing pattern of HepG2 and RHepG2 was quite different. Upon PD treatment, the release of AO in HepG2 cells was graduate and slow while that in RHepG2 was sudden and sharp. / Cancer is one of the leading causes of death in the world. During cancer treatment, development of multidrug resistance (MDR) is always the major cause of failures of chemotherapy in human cancers. In our project, hepatocarcinoma HepG2 and its drug-resistant derivatives RHepG2 with MDR towards doxorubicin (Dox), fenretinide and Taxol were used to examine the differences in their response towards various anti-cancer agents. / From the AO staining, most of the lysosomes were found in the cytosol near the nucleus. However, some lysosomes were found inside the nucleus occasionally. When we double stained the HepG2 cells with DiOC6(3), it was found that the lysosomes were actually located inside the nuclear tubules. However, no such lysosome migration was observed after treating the HepG2 cells with PD. Thus, lysosomes inside the nuclear tubules might not be involved in the PD-induced lysosomal pathway. The mechanism that leads to the migration of lysosomes into the nuclear tubules is still unclear. / From the Western blot analysis, cathepsin D (Cat D) and cathepsin L (Cat L) were both released from the lysosomes after treating the two cell lines with PD. Also, it seemed likely that Cat L was released earlier than that of cyt c. This implies that lysosomal permeabilization is an early event in apoptosis. With the use of siRNA technology, it was found that RHepG2 with the knockdown of Cat D and Cat L were more tolerant and vulnerable towards PD, respectively. These suggest that Cat D and Cat L might act oppositely in the apoptotic pathway. Furthermore, the addition of Cat D inhibitor, pepstatin A, blocked the PD-mediated cell death in RHepG2 cells further confirms that Cat D is a pro-apoptotic protein that is involved in the apoptotic pathway. / In conclusion, PD was a potent anti-cancer agent that could reverse the MDR properties of RHepG2 and kill more RHepG2 cells through lysosomal and mitochondrial apoptotic pathway. / Next, we investigated the underlying killing mechanism and found out that PD switched on both the mitochondrial and lysosomal apoptotic pathway in both cell lines. Our results indicate that PD was able to depolarize mitochondrial membrane potential and release apoptosis inducing factor (AIF) and cytochrome c (cyt c) from the mitochondria to cytosol. Also, PD was able to act on isolated mitochondria directly, causing a stronger mitochondrial membrane permeabilization and more AIF release from the RHepG2 than that of the parental cells. / Polyphyllin D (PD) is a saponin found in a tradition Chinese herb, Paris polyphylla, which has been used to treat liver cancers in China for many years. Interestingly, from the MTT assays, we found out that RHepG2 (IC50: 2.0 muM) was more sensitive towards PD when compared to that of its parental cells (IC50: 3.9 muM). To keep the MDR properties, RHepG2 cells were routinely cultured with 1.2 muM of Dox. When we cultured RHepG2 in the absence of Dox but with 1.2 muM of PD for 28 days, the Pgp expression could not be maintained. However, such high expression level of Pgp was maintained when RHepG2 cells were treated with vincristine (1.2 muM) in the absence of Dox. This indicates that vincristine was a substrate of Pgp to keep the Pgp expression in RHepG2 cells while PD was not. / When incubated with different concentrations of Dox, RHepG2 accumulated less Dox than that of its parental HepG2 cells. When probed by the antibody against P-glycoprotein (Pgp), RHepG2 showed a strong Pgp expression. With the addition of Pgp modulator, verapamil, RHepG2 accumulated more Dox. All these findings indicate that Pgp is a mediator giving rise the MDR in RHepG2 cells. However, RHepG2 had a higher resistance to Dox than its parental line even co-cultured with verapamil. RHepG2 remained viable at the intracellular Dox concentration that was toxic to HepG2 cells. These observations suggest that the MDR properties of RHepG2 involved multiple mechanisms in addition to the effect of Pgp. / Lee, Kit Ying Rebecca. / "August 2007." / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4735. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 241-253). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
387

Cancer stem-like cell properties of drug-resistant nasopharyngeal carcinoma cells. / CUHK electronic theses & dissertations collection

January 2013 (has links)
Choi, Pui Ying. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 101-122). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.
388

Clinical application of laparoscopic ultrasonography and lymphadenectomy in the management of cervical carcinoma. / CUHK electronic theses & dissertations collection

January 2012 (has links)
Cheung, Tak Hong. / "July 2011." / Thesis (M.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 166-199). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
389

Studies towards a second-generation synthesis of the aplyronines

Anzicek, Nika January 2017 (has links)
The aplyronines are a family of 24-membered macrolides of polyketide origin, isolated from the Japanese sea hare Aplysia kurodai. They exhibit an exceptional biological activity profile, acting through an actin and tubulin dual-targeting mechanism, with subnanomolar growth inhibitory potency against a diverse range of cancer cell lines. These characteristics render the aplyronines ideal payloads for antibody-drug conjugates but their prohibitively low natural abundance calls for an efficient total synthesis to overcome the supply issue. This dissertation describes the efforts towards developing a second-generation Paterson synthesis of the macrocyclic core of the aplyronines, focused on improving the scalability and selectivity of key transformations. Chapter 1 details the isolation, biological background and previous synthetic efforts towards the aplyronines to illustrate their therapeutic potential and the challenges associated with material sourcing by chemical synthesis. Chapter 2 presents the existing body of work on the aplyronine project within the Paterson group, highlighting the lessons learned over the past two decades and shortcomings to be addressed. Chapter 3 discusses a revised protecting group strategy towards the C1-C27 macrocyclic alcohol 159 with fewer manipulation steps. A refined reaction sequence featuring titanium aldol methodology and an enzymatic desymmetrisation process delivered multigram stocks of the C15-C27 aldehyde 161 upon scale- up, testifying to the robustness of the devised route. Synthesis of the C1-C14 northern fragment 253 closely followed the existing boron aldol approach with optimisation of the C11-C12 alkylation step, geared towards enhancing the regioselectivity. Chapter 4 describes the coupling of the two major fragments using an Horner-Wadsworth-Emmons reaction to assemble the C1-C27 backbone of the cyclic aplyronine core and suitably adjusted endgame steps to enable a one-step oxidative unmasking of the macrolactonisation sites. The first-generation intermediate 159 was accessed via site-specific Yamaguchi esterification and orthogonal deprotection of the C27 allyl carbonate. Discussion in Chapter 5 includes the appendage of the C28-C34 side chain 118, prepared by the known sequence, and suggestions for the future direction of the second-generation route with the outlook of linker appendage for the purposes of antibody-drug conjugate development.
390

A cancer protocol writer's assistant

Masand, Brij, 1957- January 1982 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: leaves 90-91. / by Brij Mohan Masand. / M.S.

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