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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.
1

Effects of dietary stearic and linoleic acid on mammary carcinogenesis and longevity of aging strain A/ST mice

Rogers, Wendy J. January 1998 (has links)
This investigation studies the effects of diets containing varying amounts of linoleic acid (a polyunsaturated fatty acid) and stearic acid (a saturated fatty acid) on tumorigenesis, weight and longevity in strain A/ST mice. Linoleic acid [ 18 carbons and 2 double bonds (18:2)] was chosen to represent a fatty acid known to enhance tumorigenesis and obesity in certain strains of mice. Stearic acid [ 18 carbons and no double bonds (18:0)] represents a saturated fatty acid known to increase the latency period for mammary tumor development and to decrease the rate of tumor growth. This study was conducted to determine whether the effects of fatty acids observed in younger mice on time to tumor, survival and body weights were also found in aging animals. Further, by varying the amount of linoleic acid in the diet, this study examined whether the tumor enhancing effects of increasing amounts of linoleic acid could be overcome by the incorporation of dietary stearic acid. All diets had equal percentages, by weight, of protein, salt, sucrose, mineral salt, and vitamin levels and an equal number of calories per gram of food. The SF diet was rich in linoleic acid. The SA-1 diet contained enough linoleic acid to prevent essential fatty acid deficiency, and the SA-4 diet contained the maximal amount of linoleic acid for tumor enhancement. Total body weight and tumor production in the three dietary groups show a relationship between an increase in body weight and tumor production as the amount of dietary linoleic acid increases. There also is an inverse relationship between animal survival and body weight as the amount of dietary linoleic acid increases. Survival thus appears to be dependent on tumor production in the three dietary groups, where there appears to be an inverse relationship between survival and time to tumor as the amount of dietary linoleic acid increases at each timepoint. These results suggest that the inclusion of stearic acid in the diet can, in part, overcome this enhancing effect of linoleic acid, even at the optimal tumor producing level of linoleic acid. The results of this study indicate that that effects of linoleic and stearic acid in aging mice are similar to those in younger animals. / Department of Biology
2

Antitumor properties of kefir : possible bioactive component(s) and mechanism(s)

Chen, Chujian, 1966- January 2005 (has links)
Research on the putative health benefits has indicated that kefir, a traditional fermented milk, might have antimutagenic and antitumor properties. The major objective of the present thesis was to isolate and identify antitumor compounds in cow's milk kefir and investigate the possible mechanisms involved. High speed centrifugation (HSC), molecular weight cut-off filtration (MWCO), size exclusion high performance liquid chromatography (SEC-HPLC) and reverse phase-HPLC (RP-HPLC) were utilized for fractionation of kefir and a cell culture model was developed to screen for the antiproliferative effects of the kefir fractions. The antiproliferative effects of bacteria-free extracts from different fermentation stages of kefir production, as well as bacteria-free extracts from milk and yogurt were compared. The results showed that extracts from an early stage of fermentation (i.e., kefir mother culture) and the final commercial kefir product both exerted dose-dependent inhibition effects on human mammary tumor MCF-7 cells, yogurt extracts showed less potent antiproliferative effects, while pasteurized milk extracts showed no antiproliferative effects. No antiproliferative effects of the kefir extracts were observed on human mammary epithelial cells (HMEC) whereas the yogurt extracts showed antiproliferative action in HMEC cells at a high dose. A fraction of the kefir mother culture isolated by HSC, MWCO and RP-HPLC contained components that inhibited MCF-7 cell growth and had no effect on HMEC cells. Characterization of the bioactive fraction using mass spectrometry (MS) indicated that the main components in the fraction are likely fragments of kefiran and/or ceramide containing compounds such as gangliosides. The growth inhibitory effect may be mainly caused by the induction of TNF-alpha in MCF-7 cells. Whole extracts of kefir depleted glutathione (GSH) in MCF-7 cells, while the SEC-HPLC Fraction 7 and the RP-HPLC Fraction 30 induced GSH produc
3

Antitumor properties of kefir : possible bioactive component(s) and mechanism(s)

Chen, Chujian, 1966- January 2005 (has links)
No description available.
4

Effect of diet modification on breast cancer development and cholesterol metabolism.

January 2012 (has links)
非傳染性疾病是目前全球最常見的疾病之一。不健康的食相信是導致非傳染性疾病增加的主要因素之一。因此,我們就食對乳腺癌的形成和膽固醇代謝調控的影響進行了研究。 / 在去除卵巢的祼鼠模型中,我們研究了長期和短期熱量限制對乳腺癌腫瘤增殖的影響。14週齡的小鼠被隨機分為5組:自由攝食組 (AL);熱量攝入控制在AL80% 的20%CCR組;熱量攝入控制在AL的70% 的30%CCR組;熱量攝入控制在AL的65% 的35%CCR組和短期熱量限制 (SCR)組 (前3.5週熱量攝入控制在AL的65%,之後的13.5週自由攝食)。10週後,熱量限制組的腫瘤體積明顯較AL組小 (P < 0.05)。排除攝食對體重的影響,SCR組的腫瘤重量明顯較AL組小 (P < 0.05)。本實驗結果表明,在此動物模型中,短期熱量限制能有效抑制乳腺癌細胞的增殖。 / 此外,我們還研究了芹菜素在肝細胞中對膽固醇代謝的影響。芹菜素是一種常見的黃酮類化合物。研究發現,在WRL-68細胞中,芹菜素能夠劑量依賴性的抑制3 - 羥基-3 - 甲基 - 戊二酸單酰輔酶還原酶 (HMGCR)和固醇調節元件結合蛋白-2 (SREBP-2) 信使RNA和蛋白的表達及其啟動子的轉錄活性。綜上所述,在肝細胞中,芹菜素能有效抑制HMGCR和SREBP-2的表達,從而達到降低膽固醇的效果。 / 總括而言,本研究表明在去除卵巢的祼鼠模型中,短期熱量限制能有效抑制乳腺癌細胞的生長和芹菜素能有效抑制HMGCR和SREBP-2的表達。 / Non-communicable diseases (NCD) are one of the leading causes of mortality in the developed and under-developing countries. Diet is a major risk factor of NCD. In the present study, effects of diet modification on breast cancer development and cholesterol metabolism were investigated. / In the first part of this study, the effect of chronic and short-term calorie restriction (CR) on breast tumor growth in ovariectomized nude mice was investigated. The calorie-restricted dietary regimen limited the total fat intake only. 14 week-old ovariectomized female nude mice were randomly assigned to ad libitum fed (AL), 20%CCR (17-week 80% of AL), 30%CCR (17-week 70% of AL), 35%CCR (17-week 65% of AL) and short-term CR (3.5-week 65% of AL followed by 13.5-week 100% AL consumption) groups. Starting from 10 weeks after transplant of cells, the tumor volumes in all calorie-restricted groups were significantly smaller (P < 0.05) than that in ad libitum control. At sacrifice, the tumor weight in short-term CR was significantly smaller (P < 0.05) than that in ad-libitum control after normalized with body weight. This indicated that short-term CR could suppress tumor in this model. / In the second part of this study, the effect of apigenin on cholesterol metabolism was investigated. Apigenin is one of the most abundant flavonoids. In the present study, we investigated the effect of apigenin on several cholesterol-related gene expression in hepatic cells. In WRL-68 cells treated with apigenin, promoter transcription activity, mRNA and protein expression of HMGCR and SREBP-2 were significantly decreased in a dose-dependent manner. Taken together, we concluded that apigenin inhibited HMGCR and SREBP-2 gene expressions in hepatic cells, which might elicit the hypocholesterolemic effects. / In conclusion, our study has demonstrated that short-term CR could significantly block the breast tumor growth in a mice model and apigenin could inhibit the expression of HMGCR and SREBP-2 in liver cell lines. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wong, Tsz Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 83-99). / Abstracts also in Chinese. / ACKNOWLEGEMENTS --- p.i / ABSTRACT --- p.ii / 摘要 --- p.iv / list of abbreviations --- p.v / list of figures --- p.vii / list of tables --- p.IX / TABLE of CONTENTS --- p.X / Chapter 1 --- CHAPTER 1 --- p.1 / General Introduction --- p.1 / Chapter 1.1 --- Calorie Restriction and the Prevention of Postmenopausal Breast Cancer --- p.2 / Chapter 1.1.1 --- Breast Cancer --- p.2 / Chapter 1.1.2 --- Epidemiology of Excess Body Weight and Cancer Risk --- p.3 / Chapter 1.1.3 --- Calorie Restriction and Cancer Prevention --- p.7 / Chapter 1.1.4 --- Mechanistic Targets of Calorie Restriction --- p.8 / Chapter 1.1.4.1 --- Effect of Calorie Restriction on Estrogen --- p.8 / Chapter 1.1.4.1 --- Effect of Calorie Restriction on Cell Cycle Regulation --- p.12 / Chapter 1.1.4.1 --- Effect of Calorie Restriction on Apoptosis --- p.14 / Chapter 1.2 --- Effect of Apigenin on Cholesterol Homeostasis --- p.17 / Chapter 1.2.1 --- Cardiovascular Disease and Blood Cholesterol --- p.17 / Chapter 1.2.2 --- Molecular Regulation of Cholesterol Metabolism --- p.21 / Chapter 1.2.2.1 --- HMG-CoA Reductase --- p.21 / Chapter 1.2.2.2 --- CYP7A1 --- p.24 / Chapter 1.2.2.3 --- Apolipoprotein A-1 --- p.26 / Chapter 1.2.2.4 --- Low Density Lipoprotein Receptor --- p.29 / Chapter 1.2.2.5 --- Sterol Regulatory Element Binding Proteins --- p.31 / Chapter 1.2.3 --- Flavonoid and its Association with Cholesterol Metabolism --- p.36 / Chapter 1.2.4 --- Apigenin: A Potential Alternative --- p.39 / Chapter 2 --- CHAPTER 2 --- p.41 / MATERIALS AND METHODS --- p.41 / Chapter 2.1 --- Chemicals and Materials --- p.41 / Chapter 2.1.1 --- Chemicals --- p.41 / Chapter 2.1.2 --- Plasmids --- p.41 / Chapter 2.2 --- Cell Culture --- p.41 / Chapter 2.2.1 --- Maintainance of Cells --- p.41 / Chapter 2.2.2 --- Preparation of Cell Stock --- p.42 / Chapter 2.2.3 --- Cell Recovery from Liquid Nitrogen Stock --- p.42 / Chapter 2.3 --- Measurement of Cell viability --- p.43 / Chapter 2.4 --- Semi-Quantitative and Quantitative RT-PCR Assay --- p.43 / Chapter 2.4.1 --- RNA Isolation and cDNA Synthesis --- p.43 / Chapter 2.4.2 --- Quantitative Real Time PCR Assay --- p.43 / Chapter 2.4.2.1 --- Real Time PCR Using TaqMan Probe --- p.43 / Chapter 2.4.2.2 --- Real Time PCR Using SYBR Green Dye --- p.44 / Chapter 2.4.2.3 --- Statistical Analysis of 2⁻ΔΔ{U+A7F0}{U+1D40} Comparative Gene Expression --- p.44 / Chapter 2.5 --- Western Blot Analysis --- p.46 / Chapter 2.6 --- Measurement of Promoter Activity --- p.46 / Chapter 2.6.1 --- Plasmid Preparation --- p.46 / Chapter 2.6.2 --- Transient Transfection and Dual-Luciferase Assay --- p.47 / Chapter 2.7 --- Animal Experiment Design --- p.47 / Chapter 2.7.1 --- Animal Model and Dietary Regimens --- p.47 / Chapter 2.7.2 --- Tissue Sample Collection --- p.50 / Chapter 2.7.3 --- Plasma Estradiol Determination --- p.50 / Chapter 2.7.4 --- Protein and RNA extraction --- p.50 / Chapter 2.8 --- Statistical Analysis --- p.50 / Chapter 3 --- Chapter 3 --- p.51 / EFFECT OF CHRONIC AND short-term calorie restriction on breast tumor growth in ovariectomized nude mice --- p.51 / Chapter 3.1 --- Introduction --- p.51 / Chapter 3.2 --- Objectives --- p.52 / Chapter 3.3 --- Results --- p.53 / Chapter 3.3.1 --- Food Intakes, Body, Liver and Uterus Wet Weights of the Mice --- p.53 / Chapter 3.3.2 --- Tumor Development --- p.57 / Chapter 3.3.3 --- Plasma Estradiol Level --- p.62 / Chapter 3.3.4 --- Estradiol Responsive Gene expression in Tumors --- p.63 / Chapter 3.3.5 --- Cell Apoptotic and Cell Cycle-Regulated Protein expression in Tumors --- p.65 / Chapter 3.4 --- Discussion --- p.67 / Chapter 4 --- CHAPTER 4 --- p.69 / Apigenin inhibits the expression of hmg-coa reductase and srebp-2 in hepatic cells --- p.69 / Chapter 4.1 --- Introduction --- p.69 / Chapter 4.2 --- Objectives --- p.70 / Chapter 4.3 --- Results --- p.70 / Chapter 4.3.1 --- Effect of Apigenin on Cell Viability --- p.70 / Chapter 4.3.2 --- Effect of Apigenin on HMGCR, CYP7A1, LDLR, ApoA-1, SREBP-1 and SREBP-2 mRNA expressions --- p.72 / Chapter 4.3.3 --- Effect of Apigenin on HMGCR, LDLR, ApoA-1 and SREBP-2 Promoter Transcription Activity --- p.75 / Chapter 4.3.4 --- Effect of Apigenin on HMGCR, SREBP-1 and SREBP-2 Protein Expression --- p.77 / Chapter 4.3.5 --- Role of Estrogen Receptor in Apigenin induced SREBP-2 Inhibition --- p.79 / Chapter 4.4 --- Discussion --- p.80 / Chapter 5 --- CHAPTER 5 --- p.82 / SUMMARY --- p.82 / References --- p.83
5

Diet, hormones and breast cancer : a case-control study in women / by Thomas Edward Rohan

Rohan, Thomas Edward January 1986 (has links)
Bibliography: v. 2, leaves [410]-464 / 2 v. : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Community Medicine, 1986?
6

Diet and exercise intervention adherence and health-related outcomes among older long-term breast, prostate, and colorectal cancer survivors

Winger, Joseph G. January 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Given the numerous benefits of a healthy diet and exercise for cancer survivors, there has been an increase in the number of lifestyle intervention trials for this population in recent years. However, the extent to which adherence to a diet and exercise intervention predicts health-related outcomes among cancer survivors is currently unknown. To address this question, data from the Reach out to ENhancE Wellness in Older Cancer Survivors (RENEW) diet and exercise intervention trial were analyzed. RENEW was a yearlong telephone and mailed print intervention for 641 older (>65 years of age), overweight (body mass index: 25.0-39.9), long-term (>5 years post-diagnosis) survivors of colorectal, breast, and prostate cancer. Participants were randomized to the diet and exercise intervention or a delayed-intervention control condition. The RENEW telephone counseling sessions were based on determinants of behavior derived from Social Cognitive Theory (SCT) (e.g., building social support, enhancing self-efficacy). These factors have been hypothesized to improve health behaviors, which in turn should improve health outcomes. Thus, drawing on SCT and prior diet and exercise research with cancer survivors, I hypothesized that telephone counseling session attendance would be indirectly related to health-related outcomes (i.e., physical function, basic and advanced lower extremity function, mental health, and body mass index) through intervention-period strength and endurance exercise and dietary behavior (i.e., fruit and vegetable intake, saturated fat intake). The proposed model showed good fit to the data; however, not all of the hypothesized relationships were supported. Specifically, increased telephone counseling session attendance was related to engagement in all of the health behaviors over the intervention period. In turn, (a) increased endurance exercise was related to improvement in all of the health-related outcomes with the exception of mental health; (b) increased strength exercise was solely related to improved mental health; (c) increased fruit and vegetable intake was only related to improved basic lower extremity function; and (d) saturated fat intake was not related to any of the health-related outcomes. Taken together, these findings suggest that SCT determinants of behavior and the importance of session attendance should continue to be emphasized in diet and exercise interventions. Continued exploration of the relationship between adherence to a diet and exercise intervention and health-related outcomes will inform the development of more cost-effective and efficacious interventions for cancer and other medical populations.

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