Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-1-11
pubmed:abstractText
With a limited subset of National Cancer Institute/National Toxicology Program (NCI/NTP) bioassays, Gaylor (Regul. Toxicol. Pharmacol. 9, 101-108, 1989) showed that the regulatory virtually safe dose (VSD), corresponding to an estimated lifetime cancer risk of less than 10(-6), could be estimated within a factor of 10 simply by dividing the maximum tolerated dose (MTD), estimated from the results of a 90-day study, by 380,000. The purpose of this current study was to extend the analysis to all carcinogens in the Carcinogenic Potency Database (CPDB) utilizing the TD50 (average daily dose rate in mg/kg body wt/day that was estimated to halve the probability of remaining tumor-free at a specified tissue site throughout a 2-year study). Using the relationship between the upper bound on the low-dose slope (q1*) and the TD50 reported by Krewski et al. (Risk Anal. 13, 383-398, 1993) and the ratio of the maximum dose tested (Max-D)/TD50 obtained in our present analysis, an estimate of the regulatory VSD was given by the MTD/740,000, for NCI/NTP rodent carcinogens. This was about a factor of two lower than the limited analysis conducted by Gaylor. There was little difference when the chemicals were divided into mutagens and nonmutagens. Ninety-six percent (134 of the 139 NCI/NTP rodent carcinogens) of the regulatory VSDs calculated from the individual TD50s obtained from the 2-year bioassays were within a factor of 10 of the MTD/740,000.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0273-2300
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
57-63
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Quick estimate of the regulatory virtually safe dose based on the maximum tolerated dose for rodent bioassays.
pubmed:affiliation
National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.