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Results 601 - 650 of 712
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Yates I E - - 1982
The use of bacterial bioluminescence as a toxicological assay for mycotoxins was tested with rubratoxin B, zearalenone, penicillic acid, citrinin, ochratoxin A, PR-toxin, aflatoxin B1, and patulin. The concentrations of mycotoxins causing 50% light reduction (EC50) in Photobacterium phosphoreum were determined immediately and at 5 h after reconstitution of the ...
Wood A W - - 1982
Ferulic, caffeic, chlorogenic, and ellagic acids, four naturally occurring plant phenols, inhibit the mutagenicity and cytotoxicity of (+/-)-7beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (B[a]P 7,8-diol-9,10-epoxide-2), the only known ultimate carcinogenic metabolite of benzo[a]pyrene. The mutagenicity of 0.05 nmol of B[a]P 7,8-diol-9,10-epoxide-2 in strain TA100 of Salmonella typhimurium is inhibited 50% by incubation of the ...
Ratnoff O D - - 1982
Ellagic acid (4,4',5,5',6,6'-hexahydroxydiphenic acid 2,6,2',6'-dilactone) can substitute for negatively charged surfaces as a stimulus to reactions of the intrinsic pathway. Incubation of solutions of 4 X 10(-6)M ellagic acid with purified HF (factor XII) induced clot-promoting and amidolytic activity. Clot-promoting activity tested on a substrate of HF-deficient plasma evolved much ...
Stich H F - - 1982
Several plant phenolics, one instant coffee, one instant decaffeinated coffee, one roasted coffee, one Japanese tea, one black Indian tea, and one Chinese tea were examined for their inhibitory properties on mutagenicity resulting from the nitrosation of methylurea. Mutagenicity was estimated as the number of his+ revertants per survivor of ...
Stich H F - - 1982
The objective of this study was to simulate in vitro at least some of the conditions that prevail in man during ingestion of nitrate and nitrosable compounds. Human saliva has been chosen because most chemicals ingested through food will interact with saliva. The nitrosation of methylurea was used as a ...
Puju S - - 1982
Two N-nitroso bile acid conjugates, N-nitrosotaurocholic acid and N-nitrosoglycocholic acid, were tested for mutagenicity by forward mutation assay in Salmonella typhimurium TM 677 and in diploid human lymphoblasts, line TK6. N-Nitrosoglycocholic acid and N-nitrosotaurocholic acid showed similar concentration-response curves in the bacterial assay with statistically significant mutant fractions observed at ...
Cox N A - - 1982
Samples of commercially pelleted poultry feed (30 g) were inoculated with nalidixic acid-resistant marker strains of Salmonella heidelberg or S. montevideo at levels of 1 (low), 20 (medium), or 40 (high) cells/g of feed, then 100 ml of either a nonselective preenrichment medium (lactose broth) or a selective enrichment medium ...
Chambers T M - - 1982
Treatment with ozone inactivates the mutagenicity of many carcinogens in aqueous solution. The colon carcinogen, 1,2-dimethylhydrazine (DMH) has been reported an exception; ozone treatment converts dimethylhydrazine from a non-mutagen into a mutagen. In the Salmonella/microsome assay, the mutagenicity of ozone-treated dimethylhydrazine was dependent on pH. The ozonation product was a ...
Gelernt M D - - 1982
Diisopropylamine dichloroacetate, the active component of many formulations of pangamic acid (trade-named "vitamin B15"), and diisopropylamine, a component of diisopropylamine dichloroacetate, both demonstrate mutagenicity in the Ames Salmonella/mammalian microsome mutagenicity test. Ninety percent of such agents prove carcinogenic, and this long-term possibility must be considered in any proposed use of ...
Negishi T - - 1982
By carrying out the pre-incubation of bacteria with N-nitrosamines under acidic conditions, the mutagenicity of N-nitrosodimethylamine on Salmonella TA100 and E. coli WP2 try, hcr was detected with increased sensitivity, compared to usual assays in neutral buffers. Using this modified assay system, compounds have been screened for their modulating effects ...
Silhánková L - - 1982
3-chloro-1,2-propanediol and 1,3-dichloro-2-propanol caused base substitutions in Salmonella typhimurium TA1535 both with and without metabolic activation. Metabolic activation seemed to act mainly by decreasing the toxicity of these compounds. A difference in the growth of the wild-type and repair-deficient strains of Escherichia coli was observed only for 1,3-dichloro-2-propanol with S9 ...
Mangino M M - - 1982
The secondary amine barley malt alkaloids N-methyltyramine and N-methyl-3-aminomethylindole were synthesized, nitrosated in dilute acetic acid and the products characterized by mass spectrometry and NMR spectroscopy. The nitrosation products of N-methyltyramine were p-hydroxy-m-nitro-N-nitroso-N-methyl-2-phenylethylamine and p-hydroxy-N-nitroso-N-methyl-2-phenylethylamine. Upon nitrosation, N-methyl-3-aminomethylindole formed N-nitroso-N-methyl-3-aminomethylindole and the dinitrosated product N1-nitroso-N-nitroso-N-methyl-3-aminomethylindole.
Kinsella A R - - 1982
High densities of wild-type, 6-thioguanine sensitive V79 cells reduce the recovery of 6-thioguanine resistant (6TGR) cells when they are co-cultivated. This metabolic co-operation effect has been reported previously to be eliminated by the tumour promoter 12-O-tetradecanoylphorbol-13-acetate and the accompanying enhancement of 6TGR colony recovery has been postulated as a rapid ...
Ashby J - - 1982
Earlier observations that substitution of the aromatic nucleus of an arylamino/nitro carcinogen with either a sulphonic acid substituent or two methyl groups placed ortho to the nitrogen substituent renders the molecule non-carcinogenic have been extended via studies conducted in vitro. 4-Aminobiphenyl-4'-sulphonic acid has been synthesized and found to be non-mutagenic ...
Weisburger E K - - 1981
Metabolic experiments have furnished leads on both the detoxification and activation pathways for aromatic amines. These consist largely of C- and N-hydroxylation, followed by conjugation with glucuronic or sulfuric acid, although other mechanisms may be involved. Current emphasis is on the N-hydroxylated derivatives as a precursor to the activated carcinogen. ...
Stich H F - - 1981
5 components of the betel quid were examined for their clastogenic activities individually and in various combinations. They included the alkaloid, arecoline, from the betel nut (Areca catechu L.), eugenol, from the betel vine (Piper belle L.), chlorogenic acid, from tobacco leaves (Nicotiana tabacum), quercetin, from fennel seeds (Foeniculus vulgare ...
Pelroy R A - - 1981
The Ames/Salmonella assay was used to determine the effect of nitrous acid on the mutagenicity of solvent refined coal (SRC) distillates and distillate fractions. The SRC materials consisted of the higher-molecular-weight, high-boiling distillates, the process solvent (PS) and heavy distillate (HD), and also included the basic tar and neutral tar ...
Weiss R - - 1981
We have examined the metabolic behavior of several triiodobenzoic acid derivatives because of the observed mutagenicity and cytotoxicity of 3-amino-5-acetamido-2,4,6-triiodobenzoate (I) and 3,5-diamino-2,4,6-triiodobenzoate (II). Measurements were facilitated using iodine-131 (131I)-labeled compounds. Drug retention in rabbits was monitored with a gamma camera. Metabolic products were studied by column and thin-layer chromatography. ...
Hayatsu H - - 1981
By using the Salmonella/microsome system, it was found that the activity of mutagens present in the basic fraction of cooked-ground-beef was completely suppressed by addition of the acidic fraction obtained from the cooked-beef. The suppression was ascribable to the presence of oleic acid in the acidic fraction. This finding indicates ...
Stich H F - - 1981
Chlorogenic acid, a compound which occurs naturally in many food items, was assayed for genotoxic activity in 3 different test systems: reverse mutations in the preincubation test with Salmonella typhimurium, gene conversion with Saccharomyces cerevisiae strain D7, and chromosome aberrations in Chinese hamster ovary (CHO) cells. Chlorogenic acid was directly ...
Chung K T - - 1981
Seventeen commonly used dyes and 16 of their metabolites or derivatives were tested in the Salmonella-mammalian microsome mutagenicity test. Mutagens active with and without added Aroclor-induced rat liver microsome preparations (S9) were 3-aminopyrene, lithol red, methylene blue (USP), methyl yellow, neutral red, and phenol red. Those mutagenic only with S9 ...
Gowda N M - - 1981
Since concern has recently been expressed about the presence of genotoxic substances due to chlorination of water and wastewater, chloramine-T (CAT) is proposed as an alternative disinfectant to chlorine. The viricidal properties of chlorine and CAT were compared. Kinetics of inactivation of poliovirus type 2 by chlorine and CAT in ...
Tsuda M - - 1981
2-Amino-alpha-carboline [26148-68-5] which was isolated from a pyrolysate of soybean globulin and which was mutagenic to Salmonella typhimurium in the presence of a rat-liver microsomal fraction (S9 mix), was converted into non-mutagenic 2-hydroxy-alpha-carboline by treatment with nitrite in acidic conditions. However, on prolonged treatment with nitrite and acid, 2-hydroxy-alpha-carboline was ...
Haugen D A - - 1981
Treatment of mutagenic primary aromatic amines with nitrous acid is known to decrease their mutagenicity. We examined some factors concerning the validity of using decreases in mutagenicity due to nitrous acid treatment as an indication of the presence of mutagenic primary aromatic amines in complex mixtures. We found that treatment ...
Hayatsu H - - 1981
An ether extract of normal human feces showed inhibitory effects on the activities of several mutagens in the Ames tests. By addition of the ether extract at an amount equivalent to 0.5 g of a sample of feces, the mutagenicity of 1.5 nmole of 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) on Salmonella typhimurium TA98 ...
Kumar S - - 1981
Immunological studies have shown an increased lymphocyte reactivity in patients with early stage bladder cancer and individuals with pre-stage T1 exposed to bladder carcinogens (2-naphthylamine and industrial 1-naphthylamine containing 4-8% 2-naphthylamine) before 1952-that is, those at high risk of developing bladder cancer. Because of the close chemical similarity of Tobias ...
Barale R - - 1981
The mutagenicity test methodology in vitro has been extensively used during recent years in the identification of potential carcinogenic agents. Mutagenic analyses have been applied to the study of chemical reaction products for the demonstration of the formation of mutagenic agents. Recent studies have indicated that secondary and tertiary amines, ...
Wilmer J - - 1981
Solutions of nucleic acid bases, nucleosides and a nucleotide, saturated with either N2, N2O or O2, were irradiated and tested for mutagenicity towards Salmonella typhimurium, with and without pre-incubation. Irradiated solutions of the nucleic acid bases were all non-mutagenic. Irradiated solutions of the nucleosides showed mutagenicity in S. typhimurium TA100 ...
DeMarini D M - - 1981
The mutagenicities of selected fractions of cigarette smoke condensate (CSC) were studied in Neurospora crassa for the presence of direct-acting mutagens. CSCs from the University of kentucky Reference Cigarette 1R1 were assayed in a forward-mutation test at the adenine-3 (ad-3) region in resting conidia of a 2-component heterokaryon. Direct-acting mutagenic ...
Sparnins V L - - 1981
The effects of glutathione S-transferases (GST) activity and acid-soluble sulfhydryl levels of a number of compounds previously investigated for their capacity to inhibit benzo[a]pyrene (BP)-induced neoplasia of the mouse forestomach were determined. Five of the compounds studied increased the GST activity of the forestomach 78-182%. The five compounds were: p-methoxyphenol, ...
Lambotte-Vandepaer M - - 1981
Urines collected from rats injected with acrylonitrile (ACN) were mutagenic towards Salmonella typhimurium TA1530; this activity was reduced when the animals were pretreated by pyrazole (inhibitor of alcohol dehydrogenase) and suppressed after pretreatment either by CoCl2 and SKF 525-A (inhibitors of the mixed-function oxidases system) or by trichloroacetonitrile (radical trapping ...
Monchaux G - - 1981
The carcinogenicity of untreated UICC chrysotile A, of acid (oxalic and hydrochloric)-leached UICC chrysotile A, of crocidolite and of JM 104 glass fibres has been studied by intrapleural injection into rats. This experiment, carried out on 304 animals, demonstrated that when more than 80% of the Mg had been leached ...
Skipper P L - - 1980
A series of hydroxamic acids (aceto-, propiono-, benzo-, and p-nitrobenzo-) and seven derivatives of these were examined for biological activity using Salmonella typhimurium. Acylation to yield O-acetyl and O-benzoyl derivatives markedly enhanced toxic properties and was necessary for mutagenic activity for all but p-nitrobenzohydroxamic acid. The dose necessary to produce ...
Katoh Y - - 1980
The mutagenicity of benzo(a)pyrene (BP) on Chinese hamster V-79 cells cocultivated with X-irradiated hamster embryo cells was inhibited by phenolic antioxidants, such as tert-butyl-4-hydroxyanisole (BHA) and butyl-hydroxytoluene (BHT), but not by disulfiram and its related compounds such as tetraethylthiuram disulfide, diethyldithiocarbamic acid and dimethyldithiocarbamic acid. The mutagenicity of BP on ...
Munakata K - - 1980
The mutagenic activity of twenty-nine new N-acylglycinohydroxamic acids and related compounds was tested on Bacillus subtilis (Rec(+), Rec(-)) and Salmonella typhimurium (TA 98, TA 100). All the N-(substituted-benzoyl)glycinohydroxamic acids, except 3-acetylaminobenzoyl-derivative, were shown to be mutagenic to both test bacteria, whereas most of the N-aliphatic acylglycinohydroxamic acids were found to ...
Nestmann E R - - 1980
About 300 compounds have been reported in the literature as constituents of pulp-mill effluent. Previously, in our screening program, 10 resin acids identified in effluent were examined for potential mutagenicity in the Salmonella/mammalian-microsome assay. Neoabietic acid was the only resin acid which was found to be mutagenic. Now, a program ...
Reddy C S - - 1980
Secalonic acid D is an acutely toxic and teratogenic mycotoxin, produced by Penicillium oxalicum in corn. Two rodent mutagenicity tests, the dominant lethal test designed to evaluate male germ cell mutations and the micronucleus test designed to evaluate somatic cell mutations, were conducted in mice to assess the carcinogenic potential ...
Namiki M - - 1980
Conditions of the reaction between sorbic acid and sodium nitrite generating mutagenic principles were examined. In the rec-assay and the Ames reversion assay, the maximal mutagenic activity was obtained in a pH range of 3.5-4.2. Mutagenic and growth-inhibitor activities of five C-nitro and C-nitroso compounds were studied. The product Y, ...
Boido V - - 1980
Sodium nitrite and two primary aromatic amines, viz. amino antipyrine (AAP) and aniline, were preincubated in vitro with human gastric juice. The resulting derivatives -- presumably diazonium salts -- were directly mutagenic in the Salmonella test. The mutagenic response was more pronounced in the case of AAP, while toxic effects ...
Hampton M J - - 1980
When the mutagen tester bacterial strain Salmonella typhimurium TA 98 was grown at different temperatures, we found that the unsaturated fatty acid composition increased at the lower growth temperatures. Membrane microviscosity, as assessed with spin-probe fatty acids using electron spin resonance, decreased as the unsaturated fatty acid content increased. These ...
Sarkar S N - - 1980
Inducible error-prone DNA repair activity was detected by infecting nalidixic acid-pretreated E. coli cells with UV-irradiated phage phi X174. Induction and decay kinetics of reactivation very much resembled that of mutagenesis of the UV-damaged phage. Repair as well as mutagenic activity increased for about 30 min. The maximal error-prone repair ...
Tsuda M - - 1980
The mutagenic aromatic amines Trp-P-1, Trp-P-2 and Glu-P-1, isolated frm pyrolysates of tryptophan and glutamic acid, at the concentration of 0.025 mM were treated with 0.05 mM nitrite at various pH values at 37 degrees C. The resulting reaction mixtures were tested for mutagenicity towards Salmonella typhimurium TA98 and TA100. ...
Schofield G M - - 1980
96 strains of facultatively anaerobic actinomycetes and 2 Propionibacterium acnes strains were studied for their ability to deaminate and/or decarboxylate 13 amino acids, to reduce nitrate and nitrite, and to produce indole, using specially adapted micro-methods. Several of the tests performed were found to provide information which may aid in ...
van Staden J J - - 1980
The effect of the addition of 2, 3, 5, 7 and 10% respectively of propionic acid on known numbers of bacteria added to or contained in carcass meal was examined. Escherichia coli was totally inhibited by 2% propionic acid, while 5% of the acid both inhibited Salmonella typhimurium and brought ...
Murphey-Corb M - - 1980
It has been observed previously that the mutagenic action of nitrous acid may be potentiated by polyamines. We examined the cellular response of two deoxyribonucleic acid repair systems to treatment with spermidine-nitrite reaction products. uvrB- deficient mutants of Salmonella typhimurium LT2 showed enhanced lethal and mutagenic response to the reaction ...
Hampton M J - - 1980
The growth temperature of the histidine auxotroph Salmonella typhimurium TA98 influences the extent of binding of 2-nitrosofluorene (NOF) to this bacterium as well as the mutagenicity of this chemical carcinogen. Gas-liquid chromatography (GLC) of bacteria grown at 37, 27 and 17 degrees C revealed that the unsaturated (hexadecenoic plus octadecenoic) ...
Tohda H - - 1980
Sister-chromatid exchanges (SCEs) in a permanent cell line of human lymphoblastoid cells were induced by 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]-indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) and 2-amino-9H-pyrido[2,3-b]indole (2-amino-alpha-carboline). The first two compounds were found in tryptophan pyrolysates, the third in a glutamic acid pyrolysate and the last in a globulin pyrolysate. All these compounds ...
Hashimoto Y - - 1980
Two potent mutagens, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), isolated from a tryptophan pyrolysate, and 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), isolated from a glutamic acid pyrolysate, modified calf thymus DNA in the presence of rat liver microsomes. The major base modified by Trp-P-2 was identified wih 3-(3-guanyl)amino-1-methyl-5H-pyrido[4,3-b]indole. The major base modified by Glu-P-1 was identified with 2-(8-guanyl)amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole. ...
Nestmann E R - - 1980
A chemical reaction occurs when trichloroacetic acid (TCA) is dissolved in dimethyl sulphoxide (DMSO), with the production of a short-lived mutagenic derivative which was detected using the Salmonella/mammalian-microsome plate overlay assay. Other interactions between test chemicals and solvents are discussed. Choice of proper solvents in mutagenicity testing is emphasized.
De Flora S - - 1980
A mutagenic response was obtained in the Salmonella/microsome reversion test by preincubating sodium nitrite and cimetidine in human gastric juice from untreated individuals, or even by adding nitrite to gastric juice samples from patients receiving cimetidine. Both base-pair substitutions (strains TA1535 and TA100) and, though very weakly, also frameshift errors ...
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