This study investigates the effect of variations in dietary vitamin E on the incidence of dimethylhydrazine-induced colonic tumors in mice. Two groups of 65 LACA mice were given 28 weekly s.c. injections of dimethylhydrazine. The only difference in the management of the two groups was the dietary content of vitamin E; one group received 10 mg/kg, and the other group received 600 mg/kg. Of these...

The fecal microflora enzymes, beta-glucuronidase and beta-glucosidase, as well as fecal bacterial counts, were examined during colon carcinogenesis in rats administered parenteral 1,2-dimethylhydrazine and fed nutritionally equivalent diets free of fiber or containing one of three single sources of dietary fiber (cellulose, hemicellulose, and pectin). Whereas pectin-fed animals had increased fe...

AIM To investigate the effect of a selective cyclooxigenase-2 (COX-2) inhibitor, rofecoxib, in the prevalence of experimental colon tumors in rats. EXPERIMENTAL DESIGN Experimental study with 35 male Sprague-Dawley rats, divided into four groups: a) control group without experimental manipulation (n = 5); b) pharmacological carcinogenesis with 1-2 dimethylhydrazine dihydrocloride (n = 10); c)...

Ornithine decarboxylase (ODC) was separated, using diethylamino-ethyl ion-exchange chromatography, into multiple peaks of activity. We investigated the isoforms of ODC during 1,2-dimethylhydrazine-induced colon carcinogenesis and in human colon tumors. ODC in both mouse and human normal-appearing colonic mucosa was consistently separated into two active peaks by diethylaminoethyl-Sepharose CL-6...

The ability of three model carcinogens, 1,2-dimethylhydrazine, di methylnitrosamine, and 2-amino-3,8-dimethylimidazo|4,5-/]qiiinoxaline, to induce mutation in a novel in vivo assay in mouse intestine has been examined. The assay is based on mutations at the Dlb-1 locus which determines the tissue specific pattern of expression of the binding site for the lectin Doltchos bifloras agglutinin. In ...

Azomethane (AM) gas was identified as a major metabolite of 1,2-dimethylhydrazine (1,2-DMH) in the expired air of F344 rats. The compound was characterized by highpressure liquid chromatography, gas chromatography, and mass spectrometry, in comparison to a synthetic standard. At a dose of 21 mg 1,2-DMH/kg sc, approximately 14 and 11% of the dose were exhaled as AM and C02, respectively, in 24 h...

The methylhydrazines, monomethylhydrazine, 1,1-dimethylhydrazine, and 1,2-dimethylhydrazine, are known carcinogens but only weak mutagens in the Ames test. Chemical oxidation of these compounds by potassium ferricyanide greatly enhanced their mutagenicity to an Escherichia coli ada mutant and converted them into inducers of the adaptive response of E. coli to alkylation damage. Enzymatic oxidat...

Cancer prevention studies were conducted with VPS, a hot water extract of the Coriolus versicolor (CV) mushroom, in female Swiss mice. The extract was administered in the diet for life to the animals. Three groups of mice received the following treatments: a). 1,2-dimethylhydrazine dihydrochloride (1,2-DMH) was administered as 10 weekly subcutaneous injections of 20 microg/g body weight, starti...

1. Walls of Staphylococcus epidermidis I2 contain 30% (w/w) of a glycerol teichoic acid containing phosphate, d-alanine and d-glucose in the molecular proportions 1:0.25:0.50. 2. The teichoic acid was isolated by extraction with trichloroacetic acid and with dilute aqueous NN-dimethylhydrazine at pH7, and was shown to be a (1-->3)-linked poly(glycerol phosphate) containing beta-d-glucopyranosyl...