Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
1990-8-24
pubmed:abstractText
A preponderance of carcinogenesis studies in rodents and epidemiologic studies in humans suggests a potential role of dietary fiber in the prevention of colorectal cancer. Recently, wheat bran fiber used as a dietary supplement has been shown to decrease the growth of rectal adenomatous polyps in patients with familial polyposis; however, few studies of high-risk human populations have been attempted to determine the effects of dietary fiber supplementation on markers of carcinogenesis in the colon or rectum. We have designed a one-arm study to evaluate the effects of dietary supplementation with wheat bran fiber [i.e., 13.5 g/day for 8 wk; after 1 mo, 2 g/day (compliance evaluation period)] on [3H]thymidine rectal mucosa cell labeling (i.e., percent of epithelial cells incorporating [3H]thymidine into DNA in intact rectal crypt cells over a 90-min exposure as well as in minced rectal biopsy tissue over a 24-hr exposure) in rectal biopsy specimens. The biopsy specimens were obtained at sigmoidoscopy in 17 compliant patients with a history of resected colon or rectal cancer. We categorized patients as having initially low or initially high [3H]thymidine-labeling indices (i.e., percent of mucosa cells that incorporate [3H]thymidine into DNA during 1.5- or 24-hour in vitro incubations) by using the median baseline labeling index as a cutoff between high and low values. On the basis of a chi-square test used to identify patients with a statistically significant (P less than .001) change, six of the eight patients who initially had high 24-hour outgrowth labeling indices showed a significant decrease in the rectal mucosa biopsy specimens obtained after treatment. An overall 22% decrease was observed in rectal mucosa cell biopsy specimens obtained at study termination (P less than .001). Of the eight patients with initially high total [3H]thymidine-labeling indices in crypt organ culture, four had a significant (P less than .001) decrease from baseline values, one had a significant increase, and three showed no change following the fiber intervention. The wheat bran fiber dietary supplement of 13.5 g/day was well tolerated by this group of older (54-70 yr) patients. Although the [3H]-thymidine labeling index data suggest that the wheat bran fiber supplement can inhibit DNA synthesis and rectal mucosa cell proliferation in high-risk patients, the results of this small pilot study should not be overinterpreted vis à vis the potential role of wheat bran fiber as a chemopreventive agent for colorectal cancer.(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0027-8874
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
82
pubmed:owner
NLM
pubmed:authorsComplete
N
pubmed:pagination
1280-5
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:2165179-Aged, pubmed-meshheading:2165179-Biopsy, pubmed-meshheading:2165179-Cell Division, pubmed-meshheading:2165179-Clinical Trials as Topic, pubmed-meshheading:2165179-Colonic Neoplasms, pubmed-meshheading:2165179-Colorectal Neoplasms, pubmed-meshheading:2165179-DNA, pubmed-meshheading:2165179-Dietary Fiber, pubmed-meshheading:2165179-Epithelial Cells, pubmed-meshheading:2165179-Epithelium, pubmed-meshheading:2165179-Evaluation Studies as Topic, pubmed-meshheading:2165179-Female, pubmed-meshheading:2165179-Follow-Up Studies, pubmed-meshheading:2165179-Humans, pubmed-meshheading:2165179-Intestinal Mucosa, pubmed-meshheading:2165179-Male, pubmed-meshheading:2165179-Middle Aged, pubmed-meshheading:2165179-Organ Culture Techniques, pubmed-meshheading:2165179-Rectal Neoplasms, pubmed-meshheading:2165179-Time Factors, pubmed-meshheading:2165179-Triticum, pubmed-meshheading:2165179-Tritium, pubmed-meshheading:2165179-Tumor Cells, Cultured
pubmed:year
1990
pubmed:articleTitle
Effects of dietary wheat bran fiber on rectal epithelial cell proliferation in patients with resection for colorectal cancers.
pubmed:affiliation
Department of Medicine, College of Medicine, University of Arizona, Tucson.
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't