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Results 551 - 600 of 710
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Osterloh J - - 1984
The transformation of n-butyl nitrite added to whole blood, plasma, and water was studied using anion exchange high pressure liquid chromatography, spectrometry, and gas chromatography. Butyl nitrite is predominantly converted to butanol, nitrite, and nitrate in acidic water and to butanol, nitrate, and methemoglobin in whole blood; however, butyl nitrite ...
Macdonald I A - - 1984
Volatile mutagens derived from sodium nitrite buffered at various pH values or in the presence of human feces were detected using Ames Salmonella tester strain TA 1535 on petrie plates inverted over samples. Volatile mutagenicity increased as the pH decreased and was primarily a function of the nitrous acid produced ...
Ohgaki H - - 1984
2-Amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole and 2- aminodipyrido [1,2-a:3',2'-d]imidazole, potent mutagens from glutamic acid pyrolysate, were given orally to CDF1 mice of both sexes at concentrations of 0.05% in pellet diet. 2-Amino-3-methyl-9H-pyrido[2,3-b]indole and 2-amino-9H-pyrido[2,3-b]indole, potent mutagens from soybean globulin pyrolysate, were given to CDF1 mice of both sexes at concentrations of 0.08%. Hepatocellular carcinomas ...
Rashid K A - - 1984
Since amino acid conjugates are plant metabolites of the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), 5 amino acid conjugates (aspartic acid, glutamic acid, leucine, methionine and tryptophan) of 2,4,5-T were tested for possible mutagenic activity utilizing 5 strains of Salmonella typhimurium (TA97, TA98, TA100, TA1535 and TA1538) with and without rat-liver microsomal ...
Linnainmaa K - - 1984
Phenoxy acid herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-methylphenoxyacetic acid (MCPA) have been found to induce proliferation of peroxisomes in the liver cells of rodents in the same manner as the hypolipidemic drug clofibrate. Both phenoxy acid herbicides and clofibrate (ethyl-alpha-p- chlorophenoxyisobutyrate ) are suspected carcinogens. The present study reports the ...
Sorenson W G - - 1984
Cyclopiazonic acid was shown to be mutagenic to Salmonella typhimurium TA98 and TA100 in the presence of metabolic activation. The activity of cyclopiazonic acid in the presence of aflatoxin B1 was studied in complete factorial experiments with strain TA98. Both mycotoxins produced significant mutagenic activity and in combination. The activity ...
Jägerstad M - - 1984
A mixture of creatinine, glucose and glycine was heated in diethylene glycol containing 14% water for 2 h at 128 degrees C, and the mutagens formed were purified by XAD-2 column chromatography, acid-base partition, Sephadex LH-20 column chromatography, 'blue cotton' treatment and HPLC. Two mutagenic substances were isolated by HPLC. ...
Schmeiser H H - - 1984
One of the 2 main components of the commercially available carcinogenic aristolochic acid (AA) was isolated, the other was enriched. Three different aristolochic acid samples (AAI 99% pure; AAI 65% + AAII 35%; AAI 32% + AAII 68%) were assayed for mutagenic activity in Salmonella typhimurium TA1537, TA100 and TA100 ...
Lipczynska-Kochany E - - 1984
11 pyridine- and 6 quinoline-carbohydroxamic acids were tested for mutagenicity on Salmonella typhimurium TA100 and TA98. The results are compared with those obtained for benzohydroxamic acid and 4 naphthohydroxamic acids. Most of them were mutagenic on both these tester strains. Of the pyridine derivatives, pyridine-2-carbohydroxamic acid was the most potent ...
Negishi T - - 1984
Saturated fatty acids, C5-C12, inhibited the mutagenic activity of N-nitrosodimethylamine (NDMA) in E. coli WP2 uvrA/pKM101. The inhibition by laurate (C12) was due to the suppression of the enzymatic demethylation of NDMA, whereas that by caprate (C10) was simply due to the bactericidal effect of the fatty acid. Caproate (C6) ...
Shibamoto T - - 1984
Usnic acid (the most abundant lichen constituents), physodic, and physodalic acids isolated from Hypogymnia enteromorph (Ach.) Nyl. were tested for mutagenicity in the Ames Salmonella/microsome assay. Physodalic acid exhibited clear dose-related mutagenicity against Salmonella typhimurium strain TA 100 with or without S9 mix in both plate-incorporation and preincubation assays. The ...
Reali D - - 1984
Mutagenic activities of a sample of characterized airborne particulates collected in a rural location near Ispra (Italy) during the summer of 1980 were detected by the Ames test using TA 1537, TA 1538, TA 98, and TA 100 Salmonella strains. Eight chemical classes fractionated from the CH2Cl2 extract of the ...
Lunn G - - 1984
The chemical degradation of five N-nitrosamides used widely for the experimental induction of cancer has been studied with the goal of identifying, and experimentally validating, reliable methods that can be recommended for the destruction of carcinogenic N-nitrosoureas and related compounds in laboratory wastes. Although data are not yet complete, preliminary ...
Röper H - - 1984
N-(1-Deoxy-D-fructos-1-yl)-L-amino acids (fructose amino acids), Amadori compounds, are formed by reaction of D-glucose and L-amino acids and Amadori rearrangement. They are detected in heat-processed natural products and various foodstuffs and are key products of the Maillard-Browning reaction. N-Nitroso-N-(1-deoxy-D-fructos-1-yl)-L-amino acids (N-NO-fructose amino acids), N-NO-Amadori compounds, are formed in high yields by ...
Wakabayashi K - - 1984
Soya sauce showed marked direct-acting mutagenicity toward Salmonella typhimurium TA 100 after nitrite treatment. Three precursors showing mutagenicity after nitrite treatment were isolated from soya sauce. Their structures were determined to be (-)-(1S,3S)-1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid [(-)-(1S,3S)-MTCA], its stereoisomer (-)-(1R,3S)-MTCA and tyramine. The numbers of revertants of TA 100 induced by 1 ...
Shinohara K - - 1983
The formation of mutagens by amino-carbonyl reactions of 20 kinds of amino acid and sugars after heating at 100 degrees C for 10 h was examined by the Ames test. The browned solutions of Gly, Ala, Val, Leu, Ile, Ser, Thr, Gln, Lys X HCl, Arg, Phe, Cys, Met and ...
Corbett M D - - 1983
The synthesis and purification of N-hydroxy-N-formyl-p-phenetidine (N-OH-FP) is described. This new compound was subjected to mutagenicity testing using Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and TA1538 both in the presence and absence of the post-mitochondrial fraction of rat liver homogenate. Simultaneous mutagenicity testing of the known phenacetin metabolite, N-hydroxyphenacetin ...
Mizuta M - - 1983
The mutagenicity of the leafy vegetable, Takana (Brassica juncia var. integrifolia), pickled with salt for various durations was examined. The mutagenicity increased with increasing duration of pickling time, and analysis by HPLC showed that is was caused by mutagenic flavonols. The flavonols contained in the fresh Takana as glycosides were ...
Nakamura H - - 1983
A study was performed to discover the active part in mutagenesis of [6]-gingerol, a mutagen contained in ginger Zingiber officinale (Nakamura and Yamamoto, 1982). [6]-Shogaol was isolated from the ginger by column chromatography on silica gel. [6]-Shogaol was much less mutagenic (1 X 10(3) revertants/10(8) viable cells/700 microM) than [6]-gingerol ...
Wilpart M - - 1983
Secondary biliary acids act, in vitro, as co-mutagenic agents towards 1,2-dimethylhydrazine incubated in the presence of Salmonella typhimurium strain TA 100. The present report demonstrates an important structure-activity relationship with regard to this effect. The number and position of hydroxyl substituents, the configuration at various C atoms and the stereochemistry ...
Jones R S - - 1983
Known and proposed metabolites of shikimic acid were synthesised, characterised and tested for genotoxic activity using the Salmonella/mammalian microsome mutagenicity test, the bacterial fluctuation mutagenicity test and the BHK 21 cell transformation test. Under the conditions used, none of these compounds showed any activity. However, shikimic acid itself was active ...
Rietveld E C - - 1983
Adult male Wistar rats administered i.p. with 2-chlorobenzylidene malononitrile (CS) excreted one mercapturic acid in urine. The amount of mercapturic acid determined gaschromatographically was about 4% of the dose (0.07 mmol/kg, n = 12). The structure of the mercapturic acid methylester was identified by t.l.c. and confirmed by synthesis and ...
Hartman T G - - 1983
This study was performed to determine the usefulness of the intercellular metabolic cooperation assay for analysis of a complex mixture and to compare the results obtained with previously conducted in vivo tumor promoter assays. One hundred 2R1 cigarettes were smoked according to Federal Trade Commission guidelines and the resulting condensate ...
McKillop C A - - 1983
Twenty bile acid or cholesterol derivatives were tested for mutagenicity by the Ames spot test procedure against five Salmonella typhimurium strains in the presence and absence of rat liver microsomes. No strong mutagens were identified, but four of the compounds increased the number of revertant colonies observed. Three of these ...
Bignon J - - 1983
Although all commercial forms of asbestos have been demonstrated to be carcinogenic in animals, so far epidemiological data are controversial concerning what asbestos types are the most carcinogenic and fibrogenic in humans. In order to understand the early cellular events induced by fibrous particles, different in vitro studies (hemolysis, release ...
Tsuchiya T - - 1983
The urine of the mice fed on a 15% sorbic acid diet was treated with or without beta-glucuronidase and was fractionated by XAD-2 column chromatography. The non-polar urine fraction was slightly mutagenic towards TA 98 when metabolically activated, but not towards TA 100. From the comparison of thin-layer chromatograms between ...
Kawalek J C - - 1983
The effects of lithocholic acid on the mutagenicity of 24 aromatic amines in the Ames assay were examined. When lithocholic acid was added to the Salmonella/mammalian--microsome mutagenicity system with the use of postmitochondrial supernatant fractions from livers of male inbred SD rats pretreated with Aroclor 1254 or phenobarbital, various effects ...
Meier J R - - 1983
Aqueous chlorination of humic acids results in the formation of compounds with direct-acting mutagenic activity in the Ames/Salmonella plate assay for tester strains TA98, TA100, TA1535, TA1537 and TA1538. The addition of a rat-liver microsomal fraction (S9) plus cofactors causes a substantial decrease of activity, the extent of which is ...
Chelala C A - - 1983
Exposure to visible light of growth medium containing riboflavin and indole at low concentrations created photoproducts highly toxic to Salmonella typhimurium and other bacteria. No toxicity was detected in the dark or when either of these two components was present singly. Other aromatic compounds (serotonin, indole-3-acetic acid, indole-3-propionic acid, tryptophan, ...
Torigoe T - - 1983
Several chalcone derivatives; e.g. Ro 09-0204, Ro 09-0323 and Ro 09-0501 were found to reduce markedly the revertant increase of Salmonella typhimurium TA100 by benzo(a)pyrene during the incubation with S-9 Mix. The antimutagenic activity was 100 - 700 times stronger than that of L-ascorbic acid. Effect on other mutagens, the ...
Golovinsky E - - 1983
Five newly synthesized hydrazides: L-aspartic acid dihydrazide, DL-ureido-succinic acid dihydrazide, DL-dihydroorotic acid hydrazide, orotic acid hydrazide, and 2,2'-anhydro-1-(beta-D-arabinofuranosyl)-orotic acid hydrazide were tested for mutagenicity in the Ames test. All these hydrazides except DL-ureidosuccinic acid dihydrazide were found to be non-mutagenic. The mutagenic activities of the latter compound which causes base-pair ...
Sacks L E - - 1983
Caffeine and theophylline are mutagenic at high concentration in the B. subtilis multigene sporulation test for mutagens; caffeine is a stronger mutagen than theophylline in this test. An unusually high fraction of the mutant colonies appear to be phenotypically identical, as judged by colonial morphology and microscopic appearance of the ...
Norkus E P - - 1983
In vitro data are presented to show that ascorbic acid does not have intrinsic mutagenicity towards strain TA100 of S. typhimurium if deionized water is used to prepare the incubation medium. The addition of Cu2+ ions to the bacterial medium that contains ascorbic acid, or the use of tap water ...
Gardner H W - - 1983
Five isomeric epoxyhydroxyene and epoxyoxoene fatty esters derived from hemolytic decomposition of linoleic acid hydroperoxide were tested for mutagenicity by the "Ames' top-agar incorporation method using S-9 mix derived from livers of male rats pretreated with Aroclor 1254. The epoxide fatty esters tested--methyl trans-12,13-epoxy-erythro-11-hydroxy-cis(trans)-9-octadecenoate and methyl trans-12,13-epoxy-threo-11-hydroxy-cis(trans)-9-octadecenoate (each composed of ...
Pereira M A - - 1983
The ability of seven methylating agents to form 7-methylguanine and O6-methylguanine was compared to their ability to initiate carcinogenesis as measured by the initiation of GGTase-positive foci. The seven methylating agents studied were methyl-N-nitroso-p-toluenesulfonamide (diazald), dimethylhydrazine (DMH), dimethylnitrosamine (DMN), dimethylsulfate (DMS), methyl methanesulfonate (MMS), methyl-N-nitro-N-nitrosoguanidine (MNNG) and methyl-N-nitrosourea (MNU). The ...
Barale R - - 1983
The intragastric host-mediated assay (h.m.a.) was devised and carried out with a view to assessing the formation of direct mutagens in the gastrointestinal tract of mammals. The h.m.a. consists in the injection of nitrosable compounds, NaNO2 and cells of the yeast S. pombe, by gavage into the animals' stomachs and ...
Tsuchiya T - - 1983
When mice were fed on a diet containing 15% sorbic acid for a period up to 6 months, ether extracts of the intestinal contents of the mice were not mutagenic with Salmonella typhimurium TA98, but the acidic components obtained by fractionating the ether extracts, showed slightly mutagenic activity with S. ...
Tsuda M - - 1983
The potent mutagens 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2, 62450-07-1), 2-amino-6-methyldipyrido-[1,2-a:3', 2'-d]imidazole (Glu-P-1, 67730-11-4) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ, 76180-96-6), isolated from pyrolysates of tryptophan and glutamic acid and from broiled sardines, respectively, were effectively degraded by chlorinated tap water with a concomitant loss of mutagenicity toward Salmonella typhimurium TA98 and TA100. The half-life of 10 ...
Warzok R - - 1983
In long-term experiments with Hooded rats the carcinogenic potential of 1-methyl-3(p-bromophenyl)-1-nitrosourea (Br-MPNU) could be demonstrated for the first time. Br-MPNU is formed also endogenously after combined administration of 1-methyl-3(p-bromophenyl)-urea (Br-MPU) and sodium nitrite. After repeated intragastric administration of 0.33 mmol Br-MPU and 0.73 mmol NaNO2 per kg b.w. papillomas and ...
Wilpart M - - 1983
Even though 1,2-dimethylhydrazine (DMH) is highly carcinogenic in experimental animals, it has not been shown to be clearly mutagenic in any of the short term tests in vitro. The present report demonstrates that DMH is mutagenic in the Ames test when it is incubated together with lithocholic or deoxycholic acid ...
Abel G - - 1983
The medicinal use of Aristolochia clematitis has been known for some time. The main active agent of this medicinal plant is aristolochic acid, a nitrophenanthrenecarbonic acid. Very recently, however, the Federal Health Office withdrew the licence for all drugs containing aristolochic acid, because of the well-founded suspicion that aristolochic acid ...
Slamenová D - - 1983
Induction of 6-thioguanine-resistant mutations was studied in Chinese hamster V79 cells treated with nitrofurylacrylic acid under aerobic and hypoxic conditions. The results obtained demonstrated that the mutagenic activity of this substance, less significant in aerobic conditions, was very high under hypoxic conditions. A gradual increase in mutation frequencies according to ...
Basu A K - - 1983
Malondialdehyde (MDA), a product of lipid peroxidation and prostaglandin biosynthesis, has been reported to be mutagenic and carcinogenic. Recent evidence suggests, however, that strongly mutagenic impurities are generated during the preparation of MDA that may contribute to the observed biological activity. Since MDA is widely produced in animal tissue it ...
Horwitz C - - 1983
Estrogens and compounds with estrogenic activity have been used for many years as animal growth promoters and to synchronize estrus in cows. The resorcylic acid lactones (RALS), which include zearalenone, are being used increasingly for these purposes. These estrogenic mycotoxins, now produced commercially, have teratogenic, mutagenic, and carcinogenic properties. There ...
De Flora S - - 1983
The in vitro reaction of nitrite with the histamine H2-receptor antagonist ranitidine, in acidified solutions or in human gastric juice, resulted in the formation of genotoxic derivatives, mainly eliciting base-pair substitutions in his-Salmonella typhimurium and trp- Escherichia coli and inducing an increased lethality in DNA repair-deficient bacteria. The mutagenic response ...
Lau H P - - 1983
Treatment of aflatoxicol with acid resulted in the formation of dehydrated derivatives with the 2,3 double bond either hydrated or unaffected. Chromatographic and physicochemical analyses of the purified derivatives revealed that hydration of the 2,3 double bond of aflatoxicol with simultaneous dehydration occurred when sulfuric acid was used. When a ...
Stich H F - - 1982
The objectives of this study were to simulate in vitro some of the conditions that may prevail in man during the ingestion of a meal and to quantitate the inhibitory effect of phenolics and phenolic-containing beverages on the formation of mutagenic nitrosation products. The test system consisted of nitrosating (pH ...
Friedman M - - 1982
The mutagenicity of aflatoxin B1 to Salmonella typhimurium strain TA98 decreased rapidly upon exposure of aflatoxin B1 to various thiols in aqueous solution. Mutagenic activity was reduced to control values within 24 hr with N-acetyl-L-cysteine (NAC), N-2-mercaptopropionylglycine (MPG), mercaptoethanol, reduced glutathione or mercaptopropionic acid at pH values near 4. Mercaptoacetic ...
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 ...
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