Showing papers by "Dale C. Snover published in 1994"

A Clinical Trial of Antioxidant Vitamins to Prevent Colorectal Adenoma

Abstract: Background People who consume a diet high in vegetables and fruits have a lower risk of cancer of the large bowel. Antioxidant vitamins, which are present in vegetables and fruits, have been associated with a diminished risk of cancers at various anatomical sites. We conducted a randomized, controlled clinical trial to test the efficacy of beta carotene and vitamins C and E in preventing colorectal adenoma, a precursor of invasive cancer. Methods We randomly assigned 864 patients, using a two-by-two factorial design, to four treatment groups, which received placebo, beta carotene (25 mg daily), vitamin C (1 g daily) and vitamin E (400 mg daily), or beta carotene plus vitamins C and E. In order to identify new adenomas, we performed complete colonoscopic examinations in the patients one year and four years after they entered the study. The primary end points for analyses were new adenomas identified after the first of these two follow-up examinations. Results Patients adhered well to the prescribed regimen...

Frequent polymorphism in exon 15 of the adenomatous polyposis coli gene.

Abstract: In the course of a study of tumor suppressor gene mutation in hepatoblastoma, a frequent neutral polymorphism was identified at codon 1493 in exon 15 of the gene causing adenomatous polyposis coli (APC). As the polymorphism introduces a new BsaJ1 site, DNA amplified by the polymerase chain reaction (PCR) can be rapidly screened for this polymorphism. This polymorphism can be used in cosegregation studies for presymptomatic diagnosis of APC and family studies.