dc.contributorUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-20T13:37:11Z
dc.date.accessioned2022-10-05T13:50:44Z
dc.date.available2014-05-20T13:37:11Z
dc.date.available2022-10-05T13:50:44Z
dc.date.created2014-05-20T13:37:11Z
dc.date.issued2002-03-01
dc.identifierBrazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 35, n. 3, p. 351-355, 2002.
dc.identifier0100-879X
dc.identifierhttp://hdl.handle.net/11449/12851
dc.identifier10.1590/S0100-879X2002000300010
dc.identifierS0100-879X2002000300010
dc.identifierS0100-879X2002000300010.pdf
dc.identifier5051118752980903
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/3888609
dc.description.abstractAberrant crypt foci (ACF) in the colon of carcinogen-treated rodents are considered to be the earliest hallmark of colon carcinogenesis. In the present study the relationship between a short-term (4 weeks) and medium-term (30 weeks) assay was assessed in a model of colon carcinogenesis induced by dimethylhydrazine (DMH) in the rat. Six-week-old male Wistar rats were given subcutaneous injections of DMH (40 mg/kg) twice a week for 2 weeks and killed at the end of the 4th or 30th week. ACF were scored for number, distribution pattern along the colon and crypt multiplicity in 0.1% methylene-blue whole-mount preparations. ACF were distinguished from normal crypts by their larger size and elliptical shape. The incidence, distribution and morphology of colon tumors were recorded. The majority of ACF were present in the middle and distal colon of DMH-treated rats and their number increased with time. By the 4th week, 91.5% ACF were composed of one or two crypts and 8.5% had three or more crypts, while by the 30th week 46.9% ACF had three or more crypts. Thus, a progression of ACF consisting of multiple crypts was observed from the 4th to the 30th week. Nine well-differentiated adenocarcinomas were found in 10 rats by the 30th week. Seven tumors were located in the distal colon and two in the middle colon. No tumor was found in the proximal colon. The present data indicate that induction of ACF by DMH in the short-term (4 weeks) assay was correlated with development of well-differentiated adenocarcinomas in the medium-term (30 weeks) assay.
dc.languageeng
dc.publisherAssociação Brasileira de Divulgação Científica (ABRADIC)
dc.relationBrazilian Journal of Medical and Biological Research
dc.relation1.492
dc.rightsAcesso aberto
dc.sourceSciELO
dc.subjectAberrant crypt foci
dc.subjectPreneoplastic lesion
dc.subjectColon carcinogenesis
dc.titleAberrant crypt foci and colon cancer: comparison between a short- and medium-term bioassay for colon carcinogenesis using dimethylhydrazine in Wistar rats
dc.typeArtigo


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