碩士 / 國立臺灣大學 / 職業醫學與工業衛生研究所 / 104 / Colorectal cancer (CRC) is a major cause of cancer associated morbidity and
mortality worldwide. The epidemiology of CRC varies remarkably among different population. Incidence rates are highest in the developed countries of North America, Australia, and New Zealand; intermediate in Europe and low in Asia, South America and Africa. However, the incidence rate grows rapidly in some Asian countries with westernization of life style and diet habits, such as Taiwan, South Korea, Singapore and Japan.
CRC has nowadays become the most common newly diagnosed cancer among both men and women since 2007 and leads to a huge burden in public health in Taiwan. According to the national census of Taiwan, there are more than 5000 subjects died of CRC and more than 14000 incident cases annually in our country thus CRC nowadays become one of the most challenging clinical and public health problems. Inter-regional difference in the incidence of CRC, including differences among population living in geographic proximity but with different life styles, strongly suggests that environment contributes the pathogenesis of CRC.
The environmental factors might lead to this disease through altering the risk of genetic changes. Strong evidence exists for a link between diet/life style and CRC. High-fat/low-fiber consumption, red meat consumption, and environmental carcinogens and mutagens were considered probably related to risk of CRC. Regarding dietary factors, though earlier studies indicated that low dietary fiber intake and high animal fat/red meat are closely correlated with increased risk of CRC. A group of compounds known as heterocyclic amines (HCAs) have been proposed as carcinogens. HCAs are formed in meats cooked at high temperature, and are potent mutagens and animal carcinogens; however, the carcinogenic potential in humans has not been established.
Surprisingly, systematically studies regarding the relationship between meat consumption containing HCAs and CRC were few in Taiwan. We intend to analyze HCAs in high-temperature processed meats and fishes, exposures to HCAs, and potential risk associated with HCAs exposures. The HCAs of interests in this study are mainly the frequently detected, such as IQ, MeIQ, MeIQx, and PhIP in cooked meat. We will development a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to analyze the levels of HCAs in high-temperature processed meats and fishes.
Food samples were collected from supermarkets, chain supermarkets, lunch, fast food and night markets. Samples were analyzed with C18 column after homogenization, addition of internal standards, base hydrolysis, absorption of lipid and filtration. This method provide good accuracy, precision and linearity. In 50 samples, total HCAs contents of the samples ranged between nd and 13.94 ng/g.
By using residues and intake rates collected from National food consumption database, life average daily dose (LADD) was simulated by Bayesian Statistic Markov chain Monte Carlo (BSMCMC). As the result, we can know that the exposure of HCAs in adults in Taiwan is acceptable HCAs intake level.
| Identifer | oai:union.ndltd.org:TW/104NTU05539004 |
| Date | January 2016 |
| Creators | Zhi-Xuan Jian, 簡志軒 |
| Contributors | 吳焜裕 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 129 |
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