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Please use this identifier to cite or link to this item: http://acervodigital.unesp.br/handle/11449/12851
Title: 
Aberrant crypt foci and colon cancer: comparison between a short- and medium-term bioassay for colon carcinogenesis using dimethylhydrazine in Wistar rats
Author(s): 
Institution: 
Universidade Estadual Paulista (UNESP)
ISSN: 
0100-879X
Abstract: 
Aberrant 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.
Issue Date: 
1-Mar-2002
Citation: 
Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 35, n. 3, p. 351-355, 2002.
Time Duration: 
351-355
Publisher: 
Associação Brasileira de Divulgação Científica (ABRADIC)
Keywords: 
  • Aberrant crypt foci
  • Preneoplastic lesion
  • Colon carcinogenesis
Source: 
http://dx.doi.org/10.1590/S0100-879X2002000300010
URI: 
http://hdl.handle.net/11449/12851
Access Rights: 
Acesso aberto
Type: 
outro
Source:
http://repositorio.unesp.br/handle/11449/12851
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

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