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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.
21

Fatty acids as cancer preventive tools in the dietary modulation of altered lipid profiles associated with hepatocarcinogenesis.

Abel, Stefan January 2005 (has links)
This thesis consists of a brief description on cancer, carcinogenesis, the changes in the type and level of dietary fat available in our diets over time and association with the development of certain diseases. The main focus of this research was on omega 6 and omega 3 essential fatty acids (EFA) and their interaction with regards to carcinogenesis.
22

Effect of diet modification on human fecal mutagenic activity

Bell, Penelope Anne January 1982 (has links)
Dietary factors have been implicated in the etiology of colon cancer. The salient components of high-risk diets are thought to be high intakes of meat, especially beef, and fat, especially animal fat, and low intakes of fiber. Low-risk diets are thought to be high in fiber, and low in meat and animal fat. The present study examines the effects of short-term consumption of diets hypothesized to increase or decrease the risk for colon cancer on mutagenic activity of feces. Whether the fecal mutagens responsible for the mutagenic activity observed in the study are directly involved in the etiology of colon cancer is not known. However, most known mutagens are potentially carcinogenic, and fecal mutagenic activity may be an indicator of risk for colon cancer. Six healthy adult subjects consumed the following diets in sequence a baseline diet for one week, a low-risk lacto-ovo vegetarian, high fiber diet for two weeks, and a high-risk, high meat, low fiber diet for two weeks. Quantitative daily food intake records were kept, and daily bowel habits were recorded. Fecal samples were collected at the end of each diet period. Analyses were performed of the diets for food and nutrient intake, and of feces for percent dry weight and pH. Mutagenic activity of the fecal samples was assayed using the fluctuation test for mutagens. The subjects' habitual diets, although omnivorous, were found to closely resemble a low-risk diet pattern. Analysis of the vegetarian and high meat diets confirmed that the subjects had consumed foods which respectively represented the components of high-risk and low-risk diets. The overall fecal mutagenic activity obtained with samples on the high meat diet was higher than with the vegetarian or baseline diets using Salmonella typhimurium TA 98 and TA 100. The trend towards higher mutagenicity on the high meat diet over the vegetarian diet was consistent for all six subjects using TA 100, and for five of the six using TA 98. The vegetarian and baseline diets resulted in similar overall mutagenic activity. Analysis of the fecal sample parameters using the Kruskal-Wallis one-way analysis of variance showed no significant differences among fecal samples from the three diet periods with respect to wet weight, dry weight, percent dry weight, pH or number of daily bowel movements. However, a sign-test analysis showed a significant trend (p<0.05) towards fewer bowel movements on the high meat diet than on the vegetarian diet. There were significant differences among subjects for all of the fecal sample parameters (p<0.01 or p<0.001). Spearman rank correlations were significantly positive between mutagenic activities using bacterial strains Salmonella typhimurium TA 98 and TA 100 for the baseline diet (p<0.01) and the vegetarian diet (p<0.05). There were also significant positive correlations (p<0.001) between pH and fecal mutagenicity on the high meat' diet using tester strain TA 100, and between wet weight and dry weight. The results of this study indicate that the overall mutagenic activity of human feces can be increased over a period of two weeks by the consumption of a diet high in meat and low in fiber, which is considered to be a high-risk diet for colon cancer. / Land and Food Systems, Faculty of / Graduate
23

Mutagens in feces of vegetarians and non-vegetarians

Bergstrom, Danielle Cantin January 1982 (has links)
Mutagens in feces have been suggested to be an indicator for risk of colon cancer. Groups consuming vegetarian diets are known to have lower mortality from colon cancer. The purpose of this study was to assess mutagenic activity in feces of persons habitually consuming vegetarian or non-vegetarian diets and to try to identify dietary factors or other health habits which contributed to fecal mutagenicity. Eleven strict vegetarians, six ovo-lacto vegetarians and twelve non-vegetarians, all from the Greater Vancouver area, participated in this study. Data on certain demographic variables and health habits, as well as dietary intake (food frequency and food records), were taken. One fecal sample was collected from each subject for the study. Aqueous extracts of the feces were prepared and analyzed for mutagens using the fluctuation test with Salmonella typhimurium TA100 and TA98. Levels of mutagenicity on each organism were then statistically correlated with frequency of consumption of food groups, nutrient intake, demographic data and health habits. Ovo-lacto vegetarians and strict vegetarians, as groups, had significantly lower levels of fecal mutagens than non-vegetarians in the TA100 assay. With TA98, only the strict vegetarians had lower levels of mutagens compared to the non-vegetarians. The presence of several different mutagenic compounds was indicated. Significant negative correlations were found with mutagenicity on TA98 for all subjects with the following dietary variables: fruits and juices, fiber and iron. Similar negative correlations were found for total carbohydrate and Southgate fiber intakes and mutagenicity on TA100. Within the group of non-vegetarians, there were negative correlations with mutagenicity on TA98 and total protein and with mutagenicity on TA100 and calcium. With the demographic variables and health habits, no clear pattern emerged to indicate factors which would predict lowered mutagenicity for all subjects. It is concluded that vegetarians have lower levels of fecal mutagenicity and that several dietary factors are likely to contribute to this phenomenon. / Land and Food Systems, Faculty of / Graduate
24

Feasibility of an educational intervention program on managing the nutrition impact symptom cluster in patients with nasopharyngeal carcinoma during radiotherapy

January 2016 (has links)
"Background: Nasopharyngeal carcinoma (NPC) is endemic in southern China. Despite the improvement in radiotherapy (RT) technology, NPC patients still suffer from numerous and simultaneous distressing symptoms. / Aims: The aim of the study was to explore the feasibility of an intervention program (an educational intervention program) in managing the most distressing symptom cluster (nutrition impact symptom cluster) in NPC patients during RT. / Methods: The study was carried out in two parts. Part I consisted of groundwork research (n = 130) using a cross-sectional design to identify the most distressing symptom cluster. An instrument validation was also conducted at this point. Part II covered the development process and pilot testing of an educational intervention program, guided by the Medical Research Council (MRC) framework, to manage the nutrition impact symptom cluster identified in Part I. First, to inform development of the intervention, a systematic review was conducted to evaluate the effectiveness of psychoeducational intervention (PEI), which includes the educational intervention, in managing symptom clusters in patients with generic cancers. Second, a descriptive qualitative study was conducted through face-to-face semi-structured interviews with 25 NPC patients and 16 health professionals, separately, to provide further help in developing the intervention by investigating patients’ self-care experience and current clinical practice in managing the nutrition impact symptom cluster. Third, the feasibility and estimated effectiveness of the educational intervention program was explored in a pilot randomized controlled trial (RCT) (n = 40). Outcome measures, including severity of the nutrition impact symptom cluster, body weight, functional performance and quality of life (QOL), were assessed at baseline, week 3 of RT and at the end of RT. Inferential statistics, such as independent t-test, Chi-square test, Fisher’s exact test and the generalized estimating equation (GEE) model, were used to compare the baseline and various outcome variables between groups. / Results: In Part I, the Chinese version of the MD Anderson Symptom Inventory - Head and Neck Module (MDASI-HN-C) was found to be a reliable and valid instrument. The same dataset then revealed four symptom clusters in NPC patients during RT; the nutrition impact cluster was identified as the most distressing, and was thus chosen as the target outcome of the intervention. In Part II, the systematic review found that PEI, in particular, patient education, was a promising intervention to manage cancer symptom clusters. Then, the findings of the qualitative study further informed and guided the development of an educational intervention program. The pilot RCT found that the conducting the program in a clinical setting was feasible and well received by patients. It also had some favorable effects on managing the nutrition impact symptom cluster, in terms of relieving the cluster itself (Cohen’s d = -0.37), and improving the physical well-being (Cohen’s d = -0.15) and head and neck cancer (HNC) specific QOL (Cohen’s d = -0.05). / Conclusion: The implementation of the educational intervention program appears to be feasible with NPC patients during RT, showing some effect in improving the nutrition impact symptom cluster. A future full-scale study with an adequate sample is warranted." / 研究背景:鼻咽癌在中國南部高發。儘管放療技術在進步,鼻咽癌病人在接受放療期間仍然存在著各種同時出現的症狀困擾。 / 研究目的:本研究旨在測試一個健康教育干預項目在管理鼻咽癌病人放療期間最嚴重的營養相關症狀群的可行性。 / 研究方法:本研究分為兩個部分。第一部分採用橫斷面的研究方法(n = 130),目的是為了找出最嚴重的症狀群,包括檢驗一個量表的信效度。第二部分包括健康教育干預專案的設計和預實驗。首先,研究者做了一個系統評價來評估心理及健康教育干預對管理癌症病人症狀群的效果。然後,研究者又做了一個質性研究,通過與25名鼻咽癌放療病人和16名醫護人員面對面訪談來瞭解目前營養相關症狀群的管理現狀,以便為干預的設計提供進一步線索。最後,研究者做了一個隨機對照試驗的預實驗(n = 40),來評價本研究所設計的健康教育干預專案的可行性。研究指標包括營養相關症狀群的嚴重性、體重、功能水準以及生活品質,並於干預前、放療第3周以及放療結束進行測量。統計推斷方法包括獨立樣本t檢驗、卡方檢驗、Fisher確切概率法和廣義估計方程模型,用以比較組間差異。 / 研究結果:第一部分的研究結果表明,中文版的M. D. Anderson症狀調查表(頭頸)的信效度良好。此外,四個症狀群被發現,其中以營養相關症狀群最為嚴重,因此被選為本研究的干預目標。第二部分,通過系統評價,研究者發現心理及健康教育干預,尤其是健康教育對管理癌症病人的症狀群有一定效果。接著,質性研究的結果進一步提示了健康教育干預項目的必要性,並為該專案的設計提供了具體方案。最後,預實驗表明本研究所設計的健康教育干預專案是可行的並受病人歡迎。該項目在減輕營養相關症狀群(Cohen’s d = -0.37)以及提高與身體(Cohen’s d = -0.15)和頭頸癌相關(Cohen’s d = -0.05)的生活品質上有一定效果。 / 研究結論:本研究所設計的健康教育干預專案是可行的,並對管理鼻咽癌病人放療期間的營養相關症狀群有一定效果。將來需要做一個大規模的研究來驗證該項目的有效性。" / Xiao, Wenli. / Thesis Ph.D. Chinese University of Hong Kong 2016. / Includes bibliographical references (leaves 226-250). / Abstracts also in Chinese. / Title from PDF title page (viewed on 01, February, 2018). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.
25

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?
26

Safety and efficacy of n-3 enriched nutritional supplements in the management of cancer cachexia

Klopper, Tanya 03 1900 (has links)
Thesis (MNutr (Interdisciplinary Health Sciences. Human Nutrition))--University of Stellenbosch, 2006. / Background At least 40 - 80% of all cancer patients develop some degree of clinical malnutrition and cachexia. The complex and multi-factorial nature of cancer cachexia and the inability of conventional nutrition intervention to reverse or attenuate the effects of this syndrome have driven investigators to consider new therapies and approaches to manage the syndrome of cancer cachexia including eicosapentaenoic acid (EPA), an n-3 fatty acid of fish oil origin. Objectives The aim of this study was to review Phase I, Phase II and Phase III (RCT) trials investigating the safety and efficacy of n-3 supplementation in the treatment of cancer cachexia in adult patients with unresectable solid tumours, with special reference to weight loss, body composition, appetite, dietary intake, energy expenditure, functional status, acute phase response and quality of life. Adverse effects associated with EPA supplementation were also reviewed. Methodology and data collection The major databases were systematically searched for studies that met the inclusion criteria using a structured keyword search strategy or various combinations of these keywords. Relevancy of studies was assessed by two independent reviewers according to pre-determined inclusion and exclusion criteria. Quality was assessed by two independent reviewers using the Jadad scale. Data extraction was performed by the principal reviewer and one of the independent reviewers, and investigators of the included studies were contacted where further information was required. Meta-analysis was not appropriate due to heterogeneity of the data. However, where possible, the paired t-test was used for analysis of the data. Descriptive or non-quantitative analysis of the tabulated data provided a summary of the characteristics of the included studies enabling comparisons to be made between interventions and outcomes within the specified population. Results The search resulted in a total of 1408 citations, of which only 16 studies met the inclusion and exclusion criteria. Of these, only 4 studies were of a good quality. Although the reported data was incomplete and variable, the combined analyses suggested that the effect of EPA supplementation on weight, fat mass, dietary intake, energy expenditure, and acute phase response was not significant. Interestingly there appeared to be a significant increase increased or decreased? in lean body mass (p<0.05). There was little or no data to draw any conclusions regarding the effect of supplementation on appetite and quality of life. Conclusion Despite several limitations in this review, the data collected and analysed are suggestive of the beneficial effects of EPA supplementation, but there remains a significant lack of substantial evidence and conclusive statistical analysis to confirm that EPA supplementation is a safe and effective method of intervention in the management of patients with cancer cachexia.
27

The relationship between dietary factors, meat consumption, heterocyclic amines, Benzo[a]pyrene, meat-derived mutagenic activity and colorectal cancer in Western Australia

Tabatabaei, Seyed Mehdi January 2009 (has links)
The role of meat consumption in the development of cancer, including colorectal cancer (CRC), has been subject of much investigation in recent years. The observation of geographical variation in CRC incidence and increased CRC risks in populations consuming high levels of meat prompted researchers to hypothesise a link between meat and CRC. An area of particular interest in CRC pathogenesis is the meat-derived compounds such are heterocyclic amines (HCAs), polycyclic aromatic hydrocarbons (PAHs), and meatderived mutagenic activity. Australia is among the countries with high incidence of CRC and also high levels of per capita meat consumption. Hence, clarifying the possible link between meat consumption and the risk of CRC in order that this can be translated into preventive dietary recommendations for the public is important. The objective of this thesis was to examine whether meat consumption is related to risk of CRC in an Australian population. The term meat consumption in this thesis means meaures of consumption of red and white meat that incorporate frequency and cooking method. The following hypotheses were investigated: 1. Increasing intake of meat prepared by methods that involve higher cooking temperature and time is positively associated with the risk of CRC; 2. Increasing exposure to meat-derived heterocyclic amines (HCAs) is positively associated with the risk of CRC; 3. Higher levels of exposure to polycyclic aromatic hydrocarbons (PAHs) from meat consumption is a risk factor for CRC; 4. Exposure to meat-derived mutagens increases the risk of CRC.
28

Measurement of fish consumption in population-based studies of cancer

Mina, Kym Deanne January 2007 (has links)
[Truncated abstract] The role of fish consumption and omega-3 polyunsaturated fatty acids (PUFAs) in the prevention of disease has been the subject of much investigation in recent years. A clue that these factors might be of importance was the observation that populations consuming high levels of marine omega-3 PUFAs had lower rates of morbidity and mortality from cardiovascular disease. From there, research in this area has expanded to include a range of chronic diseases and their prevention. An area of particular interest is the role of fish consumption in the prevention of various cancers. In Australia, one in three men and one in four women are expected to be diagnosed with cancer by the age of 75. Identifying preventive factors that can be translated into constructive health promotional messages is of great importance in addressing this group of diseases that has such a large impact on the health and wellbeing of the population. ... Results and conclusions Analysis of the data from the population-based case-control study suggests a protective effect of preserved fish consumption, possibly due to the high oil content of these fish. The developed questionnaire is a valid and reliable tool for measuring fish and seafood consumption as determined by regression analysis with an independent biomarker and reliability analysis using intra-class correlation. Importantly, reliability can be maintained despite asking a high level of detail from participants. For ranking according to overall fish consumption, detailed questioning is probably not necessary, however inclusion of variables representing multiple categories of fish and seafood consumption in a regression model enables us to better account for variation in blood omega-3 PUFA levels than a single variable representing overall consumption. For the purpose of questionnaire validation, plasma phospholipid and erythrocyte membrane levels of EPA and DHA are equivalent biomarkers of fish and seafood consumption. The choice between them by future investigators will be based on more practical aspects such as convenience and the fasting state of subjects. The tangible product of this thesis is additional evidence to support a protective association between fish consumption and prostate and breast cancers, and a valid and reliable questionnaire v for measuring habitual consumption of fish and seafood in a West Australian population, that could also be applied to other populations after minor adjustment for local fish and seafood consumption patterns.
29

Obesity and obesity-related markers associated with breast and colorectal cancer occurence and mortality

Gathirua-Mwangi, Wambui Grace 05 April 2016 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Purpose: Obesity is a growing public health problem and the second most preventable cause of death in the US. Obesity has been linked as a risk factor for several cancers. However, there are limited studies that have examined the roles of metabolic syndrome (MetS) and C-reactive protein (CRP), as well as change in body composition from early adulthood to late adulthood on the risk of cancer. The overall objective of this dissertation was to determine the association of obesity and obesity-related markers with breast and colorectal cancer occurrence and mortality. Methods: Three datasets were used. The first study used 4,500 asymptomatic adults who were surveyed during a colorectal cancer screening study. The second study was based on the National Health and Nutrition Examination Survey (NHANES) 2005-2010. The dataset had 172 breast cancer survivors and 2,000 women without breast cancer. The last manuscript resulted from the NHANES follow-up study (NHANES III). A total of 120 cancer deaths from breast and colorectal deaths were identified from 10,103 women aged 18 years or older. Results: Overall, obesity and obesity related markers were associated with breast and colorectal cancer occurrence and mortality. BMI change and WC change were positively associated with increased risk of advanced colorectal neoplasia (AN). WC measures (both static and dynamic) were generally a better predictor of AN compared to BMI. In the second study involving breast cancer survivors, neither MetS nor CRP were associated with having a breast cancer diagnosis. Also, none of the individual components of MetS (WC, Triglycerides, HDL, fasting blood glucose and blood pressure) were associated with a breast cancer diagnosis. In the last study, MetS was associated with increased risk of mortality from obesity-related cancers. In addition, all components of MetS, except dyslipidemia, were associated with increased risk of mortality for the obesity-related cancers. Conclusion: Obesity expressed in terms of BMI and WC, or their change, MetS and CRP are important factors in regard to the occurrence, survivorship and mortality of breast and colorectal cancer. The results of this research underscore the importance of maintaining a healthy weight.
30

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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