• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Bile-salt induction of apoptosis in human lymphoid and colonic epithelial cells: Relevance to colon cancer.

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_9603380_sip1_m.pdf
    Size:
    3.220Mb
    Format:
    PDF
    Description:
    azu_td_9603380_sip1_m.pdf
    Download
    Author
    Samaha, Hanan El-Sayed Taha.
    Issue Date
    1995
    Committee Chair
    Bernstein, Harris
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Abstract
    Death from cancer of the colon is the third leading cause of cancer death in the United States. Epidemiologic evidence indicates that life style factors and particularly a high fat western diet play an important role in colon cancer. Cheah (1990) concluded that bile salts present in the feces as the result of a high fat diet are the most important etiologic agent in colon cancer. The mechanism of action of bile salts, however, is largely unknown. Bile salts have been shown to cause DNA damage in some mammalian cell types. As a first line of defence, the cell ordinarily attempts to repair the DNA damage. However, failure to repair damage can lead the cell to commit suicide (apoptosis). Apoptosis is an active physiologic mode of cell death. In this study, apoptosis was detected using Wright-stained cytospins for lymphoid cells and one micron, plastic-embedded sections for colonic epithelial cells using the light microscope. I examined the effect of the bile salt sodium deoxycholate (NaDOC) on three types of cells: transformed human lymphocytes, normal human mononuclear cells and colonic epithelial cells. I found that NaDOC induces apoptosis in lymphoid cells. This might decrease the number of lymphocytes available to defend against mutant colonic epithelial cells that develop into tumors. Also I found that NaDOC induces apoptosis in colonic goblet cells. This induction of apoptosis was strong in colon epithelial cells from normal individuals or polyp patients at low risk for colon cancer. However, the goblet cells of the apparently normal mucosa from colon cancer patients (and polyp patients at high risk for colon cancer) were found to be relatively resistant to the apoptosis-inducing effect of NaDOC. To explain these results the following model was proposed. Under conditions of a high fat diet, bile salts, may select for a population of apoptosis-resistant cells. This may lead to repopulation of the colon with cells that do not respond to DNA damage by entering the apoptosis pathway. Rather, these cells may replicate and undergo mutation at the sites of the DNA damage. These mutations may contribute to colon carcinogenesis.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Nutritional Sciences
    Graduate College
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.