title: Molecular dosimetry of aflatoxin-N7-guanine in human urine obtained in The Gambia, West Africa.
abstract: Hepatocellular carcinoma is one of the major human cancers, causing at least 250,000 deaths each year. Two of the major risk factors for this disease are aflatoxin exposure and hepatitis B virus. This study was undertaken to explore the relationship between dietary exposure to aflatoxins and the excretion of the major aflatoxin-DNA adduct and other metabolites into the urine of chronically exposed people who were either hepatitis B virus surface antigen-positive or -negative. The diets of 20 individuals, 10 males and 10 females, with ages ranging from 15 to 56 years, were monitored for 1 week, and aflatoxin intake levels were determined for each day. Starting on the fourth day, total 24-h urines were consecutively obtained for 4 days. The subjects were generally paired for hepatitis B virus status. Preparative monoclonal antibody affinity chromatography/high-performance liquid chromatography and competitive enzyme-linked immunosorbent assays were carried out on each of the urine samples, and the relationship between aflatoxin intake values and the excretion of (a) total aflatoxin metabolites and (b) aflatoxin-N7-guanine (AFB-N7-guanine) was determined. The average intake of total aflatoxins was 12.0 micrograms for the entire study group during the 1-week collection period. However, there was considerable day-to-day variation in exposures, from a low of zero to a high of 29.6 micrograms total aflatoxins/day. Initial efforts to characterize total aflatoxin metabolites in the urine samples were made by competitive enzyme-linked immunosorbent assay. The correlation coefficient for the analysis was 0.65, with P < 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Environmental Health Sciences, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205.
authors.forename: J D
authors.initials: JD
authors.lastname: Groopman
authors.forename: A J
authors.initials: AJ
authors.lastname: Hall
authors.forename: H
authors.initials: H
authors.lastname: Whittle
authors.forename: G J
authors.initials: GJ
authors.lastname: Hudson
authors.forename: G N
authors.initials: GN
authors.lastname: Wogan
authors.forename: R
authors.initials: R
authors.lastname: Montesano
authors.forename: C P
authors.initials: CP
authors.lastname: Wild
mesh_terms: D000293:Adolescent; D000328:Adult; D016604:Aflatoxin B1 / Q000031:analogs & derivatives* / Q000652:urine; D000348:Aflatoxins / Q000009:adverse effects / Q000032:analysis* / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000453:epidemiology / Q000209:etiology; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D004032:Diet / Q000009:adverse effects; D004034:Diet Surveys; D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards; D004797:Enzyme-Linked Immunosorbent Assay; D062665:Epidemiological Monitoring; D005069:Evaluation Studies as Topic; D005260:Female; D005504:Food Analysis; D005714:Gambia / Q000453:epidemiology; D006147:Guanine / Q000031:analogs & derivatives* / Q000652:urine; D006509:Hepatitis B / Q000097:blood / Q000150:complications / Q000652:urine*; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006801:Humans; D008113:Liver Neoplasms / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
chemical_list: D000348:Aflatoxins; D006514:Hepatitis B Surface Antigens; D006147:Guanine; C028319:2,3-dihydro-2-(N(7)-guanyl)-3-hydroxyaflatoxin B1; D016604:Aflatoxin B1