Majdi M. Shahin

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The effects of retinoic acid and retinol acetate on gap junctional communication were examined in two in vitro tests. Rat liver epithelial cell line IAR 203 was used for dye transfer assays, and hamster lung fibroblast V79 cells were used for metabolic cooperation assays. A reversible dose-dependent inhibition of dye transfer was detected after a 1-hr(More)
Possible tumor-promoting activity of four flavonoids, quercetin (QC), tangeretin (TG), flavone (FO), and flavanone (FN), was examined in a rat liver short-term carcinogenesis assay as well as with in vivo and in vitro assays of inhibition of gap junctional intercellular communication (GJIC). Rat hepatocarcinogenesis was induced by aflatoxin B1 treatment(More)
Synopsis In our studies of structure-activity relationships, four aminonitrophenol isomers and eleven derivatives of 3-amino-4-nitrophenol and 4-amino-3-nitrophenol were tested for their ability to induce mutations in Salmonella typhimurium strains TA1535, TA100, TA1537, TA1538 and TA98. In the presence of an Aroclor-1254-induced rat-liver microsomal(More)
Saccharomyces cerevisiae strain XV185-14C for reversion studies was used to investigate the genetic activity of alpha-benzene hexachloride dibutyl phthalate and trichloroethylene. The results indicate that none of the three compounds was genetically active when yeast cells were treated in phosphate buffer (pH 7.0) in the absence of metabolic conversion.(More)
The genetic activity of the antimicrobial food additives AF-2 and H-193 has been investigated in Saccharomyces cerevisiae. The strains chosen for the present studies were D5 for the induction of mitotic recombinational events and XV185-14C for the induction of reversion of the mutants lys1-1, his1-7 and homs3-7. When three concentrations (25, 50 and 100(More)
The mutagenicity of six monocyclic aromatic amines (2,4-diaminoanisole, 2,4-diaminoethoxybenzene, 2,4-diaminopropoxybenzene, m-phenylenediamine, 2,4-diaminotoluene, and nitro-p-phenylenediamine) was investigated in Salmonella typhimurium strains TA97, TA1537, and TA1538 in the presence of two different amounts of Aroclor 1254-induced S9 preparations. Strain(More)
In order to explore structure-activity relationships, 4,4'-diaminoazobenzene and four structurally related azo dyes were tested for their ability to induce gene mutations in Salmonella typhimurium strains TA1535, TA100, TA1537, TA1538, and TA98. Only 4,4'-diaminoazobenzene and 4,4'-N(beta-hydroxyethylamino)azobenzene were found to be active in the two(More)
This review analyzes relationships between chemical structure and biological activity for several series of compounds. Its focus is on mutagenicity and carcinogenicity and the predictability of these properties on the basis of the chemical structure. Examples are selected from monocyclic aromatic amines, benzidine derivatives, aminoazobenzene derivatives,(More)
Six 2,4-diaminoalkoxybenzenes were examined for their ability to induce mutation in Salmonella typhimurium. Each compound was tested at 8 concentrations in 5 strains. The mutagenicity was influenced by the size of the alkoxy group substituted at the C1 position of 2,4-diaminobenzene. When S9 induced by Aroclor 1254 was present, 2,4-diaminoanisole (the(More)