<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Maureen van den Donk</style></author><author><style face="normal" font="default" size="100%">Linette Pellis</style></author><author><style face="normal" font="default" size="100%">Jimmy W Crott</style></author><author><style face="normal" font="default" size="100%">Manon van Engeland</style></author><author><style face="normal" font="default" size="100%">Pieter Friederich</style></author><author><style face="normal" font="default" size="100%">Fokko M Nagengast</style></author><author><style face="normal" font="default" size="100%">Jeroen D van Bergeijk</style></author><author><style face="normal" font="default" size="100%">Sybrand Y de Boer</style></author><author><style face="normal" font="default" size="100%">Joel B. Mason</style></author><author><style face="normal" font="default" size="100%">Frans J Kok</style></author><author><style face="normal" font="default" size="100%">Jaap Keijer</style></author><author><style face="normal" font="default" size="100%">Ellen Kampman</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Folic acid and vitamin B-12 supplementation does not favorably influence uracil incorporation and promoter methylation in rectal mucosa DNA of subjects with previous colorectal adenomas</style></title><secondary-title><style face="normal" font="default" size="100%">The Journal of Nutrition</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">80 and over</style></keyword><keyword><style  face="normal" font="default" size="100%">Adolescent</style></keyword><keyword><style  face="normal" font="default" size="100%">Adult</style></keyword><keyword><style  face="normal" font="default" size="100%">Aged</style></keyword><keyword><style  face="normal" font="default" size="100%">Colorectal Neoplasms</style></keyword><keyword><style  face="normal" font="default" size="100%">Erythrocytes</style></keyword><keyword><style  face="normal" font="default" size="100%">Female</style></keyword><keyword><style  face="normal" font="default" size="100%">Folic Acid</style></keyword><keyword><style  face="normal" font="default" size="100%">Genetic</style></keyword><keyword><style  face="normal" font="default" size="100%">Genotype</style></keyword><keyword><style  face="normal" font="default" size="100%">Homocysteine</style></keyword><keyword><style  face="normal" font="default" size="100%">Humans</style></keyword><keyword><style  face="normal" font="default" size="100%">Intestinal Mucosa</style></keyword><keyword><style  face="normal" font="default" size="100%">Male</style></keyword><keyword><style  face="normal" font="default" size="100%">Middle Aged</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidoreductases Acting on {CH-NH} Group Donors</style></keyword><keyword><style  face="normal" font="default" size="100%">Promoter Regions</style></keyword><keyword><style  face="normal" font="default" size="100%">Uracil</style></keyword><keyword><style  face="normal" font="default" size="100%">Vitamin B 12</style></keyword><keyword><style  face="normal" font="default" size="100%">{DNA} Methylation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/17709451</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">9</style></number><volume><style face="normal" font="default" size="100%">137</style></volume><pages><style face="normal" font="default" size="100%">2114–2120</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Adequate folate availability is necessary to sustain normal {DNA} synthesis and normal patterns of {DNA} methylation and these features of {DNA} can be modified by methylenetetrahydrofolate reductase {(MTHFR)} {C677T} genotype. This study investigated the effect of {MTHFR} {C677T} genotype and daily supplementation with 5 mg folic acid and 1.25 mg vitamin B-12 on uracil misincorporation into {DNA} and promoter methylation. Subjects (n = 86) with a history of colorectal adenoma and {MTHFR} {CC} or {TT} genotype were randomly assigned to receive folic acid plus vitamin B-12 or placebo for 6 mo. Uracil misincorporation and promoter methylation of 6 tumor suppressor and {DNA} repair genes were assessed in {DNA} from rectal biopsies at baseline and after the intervention. The biomarkers did not differ between the treated group and the placebo group after 6 mo compared with baseline. The uracil concentration of {DNA} increased in the treated group (5.37 fmol/microg {DNA,} P = 0.02), whereas it did not change in the placebo group {(P} = 0.42). The change from baseline of 4.01 fmol uracil/microg {DNA} tended to differ between the groups {(P} = 0.16). An increase in promoter methylation tended to occur more often in the intervention group than in the placebo group {(OR} = 1.67; P = 0.08). This study suggests that supplementation with high doses of folic acid and vitamin B-12 may not favorably influence uracil incorporation and promoter methylation in subjects with previous colorectal adenomas. Because such alterations may potentially increase the risk of neoplastic transformation, more research is needed to fully define the consequences of these molecular alterations.</style></abstract><notes><style face="normal" font="default" size="100%">{PMID:} 17709451</style></notes></record></records></xml>