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Results 351 - 400 of 589
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Wakabayashi K - - 1993
Many mutagenic heterocyclic amines (HAs) have been isolated from cooked foods and pyrolysates of amino acids and proteins, and the carcinogenicity of 10 of these HAs in rodents and of 1 in monkeys has been reported. Quantification of these carcinogenic HAs in various kinds of cooked foods indicated that the ...
Boeing H - - 1993
A population-based case-control study was performed in South-West Germany in 1987/88 with 115 histological confirmed glioma and 81 meningioma cases and 418 randomly selected controls. On the basis of information from a food-frequency questionnaire and questions on food preparation and food supply, the role of dietary carcinogens, in particular N-nitroso ...
Vikse R - - 1993
The mutagenic activity in extracts of fried meat from 16 different animal species was studied in Salmonella typhimurium TA98. In each experiment, 1 meat sample together with a standard beef sample was fried, and the mutagenicity was expressed relative to the beef sample. All meat samples showed less mutagenic activity ...
Whysner J - - 1993
The evidence for BHA-induced carcinogenicity is restricted to the rodent non-glandular stomach, which is not found in humans. Although an argument can be made that an effect in this target organ could be indicative of potential carcinogenicity in other tissues, particularly the esophagus, studies have not revealed such a correlation. ...
Knize M G MG Biomedical Sciences Division, Lawrence Livermore National Laboratory, University of California, Livermore - - 1992
A series of potent heterocyclic amines that are mutagenic and carcinogenic have been discovered that are formed in some heated foods, most notably, meats derived from muscle. Determining the heterocyclic amine content in foods and food products is required for toxicological research, industry quality control, and possibly in the future, ...
Parke D V - - 1992
The use of food preservatives, such as benzoic acid, nitrites, and sulphites, as antimicrobials, and butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), ascorbic acid and tocopherols, as antioxidants, has probably changed food production patterns and eating habits more than has the use of any other class of food additive. These food ...
Walters C L - - 1992
The stabilities of nitrate and nitrite in food systems and their reactions in such matrices are reviewed. Particular reference is made to reactions with haem proteins, smoke components and amines in foods, and the chemistry of formation of N-nitroso compounds from food components is discussed. Finally, the methodology available for ...
Massey R C - - 1992
The organization of food surveillance in the UK is described, in particular as it has been applied to preservatives and their interaction products in foods. Applications of nitrates and nitrites as preservatives are discussed, together with the consequential exposure of consumers to these anions and their reaction products. Analytical methods ...
Lidbeck A - - 1992
Lactobacilli belong to the normal oropharyngeal and intestinal microflora in humans. These microorganisms contribute to the stabilization of the microflora and maintain the colonization resistance against pathogens. Lactobacilli have been used as dietary supplements in order to prevent gastrointestinal disturbances. Claims have been made that certain strains of lactobacilli possibly ...
Brams A - - 1992
The potent food mutagens and carcinogens 2-amino-3-methylimidazol[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MEIQ) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) are probably the most active bacterial mutagens so far discovered. Important discrepancies were found, however, in the specific mutagenicities published for these compounds. This paper analyzes a number of experimental factors that could explain these differences: purity ...
Hatch F T - - 1992
Aromatic amines have long been recognized as animal and human carcinogens. Recently heterocyclic aromatic amines (thermic amines) have been found in small amounts in cooked foods, primarily meats, and have proven to be potent mutagens and rodent carcinogens. Availability of quantitative databases for mutagenic potency in Salmonella and for carcinogenic ...
Hayatsu H H Faculty of Pharmaceutical Sciences, Okayama University, - - 1992
A method useful as a preconcentration technique for isolating mutagens and carcinogens is described. Cotton bearing covalently linked copper phthalocyanine trisulphonate as ligand (blue cotton) can adsorb selectively compounds having three or more fused rings. The adsorption takes place in aqueous media, involving 1:1 complex formation between the ligand and ...
Abbott P J - - 1992
The presence of a low level of potentially harmful chemicals in food continues to be a concern to many individuals. A major concern is that these chemicals, which can be synthetic or naturally occurring, may be a causative factor in human cancer. Synthetic chemicals in food may be present either ...
Ferguson L R - - 1992
The incidence of colorectal cancer is lower in Polynesian populations of the South Pacific than in European populations. This difference in incidence of the disease may be, at least partly, related to diet. Dietary fiber is believed to protect against colorectal cancer, and one of the ways it may act ...
Ford G P - - 1992
The bacterial mutagenicities of a wide variety of complex heteroaromatic amine mutagens and carcinogens present in cooked foods are approximately related to the stabilities of the corresponding nitrenium ions through equations of the kind: log(m) = a delta delta H + b. The stabilities of the nitrenium ions (delta delta ...
Tricker A R - - 1992
A review of the literature published prior to July 1991 covers the occurrence and formation of non-volatile N-nitrosamines occurring in foods and beverages. The presence of identified volatile and non-volatile N-nitrosamines accounts for less than 10% of the total apparent N-nitrosamine concentration. N-Nitrosoproline and N-nitrosothiazolidine-4-carboxylic acid are the most commonly ...
Scheuplein R J - - 1992
Epidemiologists estimate that approximately one third of all cancer deaths can be attributed to diet. It is instructive to attempt to apportion this dietary carcinogenic risk to the specific classes of foodstuffs and food additives, pesticides, etc., that are typically regulated. When this is done it is evident that virtually ...
Sivaswamy S N - - 1991
Dietary components and food dishes commonly consumed in South India were screened for their mutagenic activity. Kesari powder, calamus oil, palm drink, toddy and Kewra essence were found to be strongly mutagenic; garlic, palm oil, arrack, onion and pyrolysed portions of bread toast, chicory powder were weakly mutagenic, while tamarind ...
Balachandran B - - 1991
Several food items, commonly consumed in South India, after nitrite treatment under simulated gastric conditions were found to be mutagenic in Salmonella typhimurium tester strain TA 100. Dichloromethane extracts containing the volatile nitroso compounds and ethyl-acetate extracts with the non-volatile nitroso compounds of some of the food items exhibited mutagenicity.
Li G - - 1991
N-2-methylpropyl-N-1-methylacetonyl-nitrosamine (NMAMPA), first isolated from moldy and normal foods, was synthesized by chemical means. The structure and molecular weight of the synthetic NMAMPA were elucidated by spectrometry. A combination of spectral and chromatographic data indicated that the synthetic NMAMPA is identical to that obtained naturally. Synthetic NMAMPA is a racemic ...
Idris A M - - 1991
The aim of these studies was to determine the levels of carcinogenic tobacco specific nitrosamines (TSNA) in Sudanese oral snuff (toombak) as recent retrospective epidemiological studies suggested an association between the use of toombak and subsequent development of oral cancer. We have analyzed the TSNA levels in 20 samples of ...
Atef M - - 1991
1. The effects of nitrates and nitrites on growth, erythrocytic count, liver and kidney functions, humoral and cell mediated immune responses in cockerels were investigated. 2. Sodium nitrate (4.2 g/kg diet) and sodium nitrite (1.7 g/kg) retarded growth, caused methaemoglobinaemia and changes in erythrocytic count, serum concentrations of glutamic-pyruvic transaminase, ...
Ochiai M - - 1991
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most abundant mutagenic heterocyclic amine in cooked foods, was examined for carcinogenic potential using Nagase analbuminemic rats (NARs), which are sensitive to various carcinogens. The concentration of PhIP in the diet was 0.04% at the beginning of the experiment, this being subsequently gradually reduced to 0.01% to ...
Feron V J - - 1991
Aldehydes constitute a group of relatively reactive organic compounds. They occur as natural (flavoring) constituents in a wide variety of foods and food components, often in relatively small, but occasionally in very large concentrations, and are also widely used as food additives. Evidence of carcinogenic potential in experimental animals is ...
Felton J S - - 1991
Potent mutagenic activity in Salmonella bacteria has been reported in cooked foods in numerous laboratories worldwide. Determining the human risk from exposure to these biologically active compounds in our diet requires genotoxic and carcinogenic evaluation of the chemicals coupled with determination of the dose consumed. Thus, knowledge of the exact ...
Dipple A - - 1991
The polycyclic aromatic hydrocarbon carcinogens are formed in the inefficient combustion of organic matter and contaminate foods through direct deposition from the atmosphere or during cooking or smoking of foods. These potent carcinogens and mutagens require metabolism to dihydrodiol epoxide metabolites in order to express their biological activities. In vitro ...
Pfundstein B B German Cancer Research Centre, Institute for Chemotherapy and Toxicology, - - 1991
A simple method is described for the determination of primary and secondary amines in foodstuffs by gas chromatography with a modified thermal energy analyser, operated in the nitrogen mode. Food samples were subjected to mineral oil vacuum distillation and the isolated amines were derivatized with benzenesulphonyl chloride to form the ...
Manabe S - - 1991
The purpose of this study is to evaluate the risk of carcinogenic tryptophan pyrolysis products to human health. During the last decade, a new series of heterocyclic amines has been isolated as potent mutagens and later shown to be potent carcinogens in experimental animals. Among them, 3-amino-1, 4-dimethyl-5H-pyrido [4, 3-b]indole ...
de Kok T M - - 1991
Fecapentaenes, highly potent fecal mutagens originating from intestinal bacterial production, have been suggested to play an essential role in the initiation of colorectal cancer. Reviewing the data on fecapentaene occurrence in man, the applied methodologies for fecapentaene extraction and analysis appear to be very inconsistent. Therefore, we compared several methods ...
Tikkanen L M - - 1991
The mutagenic activities of the alkaline fractions derived from various heat-processed, ready-made meat, fish and poultry foods were studied using the Salmonella mutagenicity assay with strain TA98 and S-9 mix to provide information about the mutagenicity of everyday Finnish foods. The majority of the food samples tested were mutagenic. The ...
Naoi M - - 1991
Food-derived and carcinogenic heterocyclic amines, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), were found to inhibit the activity of tryptophan hydroxylase (TPH) prepared from serotonin-producing murine mastocytomas, P-815 cells. Inhibition of TPH by Trp-P-2 was found to be competitive with the substrate L-tryptophan and non-competitive with the cofactor (6R)-L-erythro-5,6,7, 8-tetrahydrobiopterin. The inhibition ...
Bradfield C A - - 1991
Cruciferous plant foods contain large quantities of secondary plant metabolites that have been shown to inhibit chemically induced carcinogenesis in animals. One mechanism by which these chemicals may inhibit carcinogenesis is through the induction of enzymes, such as cytochrome P-450-dependent monooxygenases, glutathione S-transferases (GST) or epoxide hydrolases (EH), which metabolize ...
Verhagen H - - 1991
Butylated hydroxyanisole (BHA) is a synthetic food antioxidant used to prevent oils, fats and shortenings from oxidative deterioration and rancidity. This review depicts the current knowledge on BHA. The physical and chemical characteristics of BHA are summarized and its function as a food antioxidant is made clear. The toxicological characteristics ...
Jägerstad M - - 1991
The formation of meat mutagens has been studied the last 10 years by carrying out modeling and meat cooking experiments in parallel. During this time, the list of meat mutagens has been growing, and continues to grow. The meat mutagens are usually produced in the crust of animal foods during ...
Eisenbrand G - - 1991
A method has been developed for the determination of the N-nitrosoalkanolamines, N-nitrosodiethanolamine (NDELA) and N-nitrosobis(2-hydroxypropyl)amine (NDHPA) in cosmetics. In model systems, we studied nitrosation of the most relevant precursors by NaNO2, by the preservatives Bronopol and Bronidox and by nitric oxides. Secondary amines were most rapidly nitrosated, and Bronopol, Bronidox ...
Bouvier G - - 1991
Representative samples of preserved foods collected from high-risk areas for nasopharyngeal carcinoma were assayed for capacity to induce Epstein-Barr virus (EBV) by measuring induction of the DR promoter gene or of genes for early antigens in Raji cells. The two assays gave concordant results, but the DR induction assay detected ...
Aeschbacher H U - - 1991
Standardized biological in vitro systems and in particular those used for cancer prediction are being used to monitor the development of food products in order to ensure the absence of potential mutagens or carcinogens. Maillard reactions occurring during meat extract production was followed in order to reduce the formation of ...
Osterdahl B G - - 1991
During the last ten years, over 900 samples of foods, snuff and other products on the Swedish market were analysed for N-nitrosamines. The average daily intake of volatile N-nitrosamines from foods was estimated to be 0.29 micrograms/person, and the daily intake of tobacco-specific N-nitrosamines from snuff was calculated to be ...
Sen N P - - 1991
We present data on the levels of both volatile and nonvolatile N-nitroso compounds in various smoked meats, including bacon, and in food contact materials (e.g., baby bottle rubber nipples and pacifiers). Evidence presented suggests that the formation of N-nitrosothiazolidine and N-nitrosothiazolidine 4-carboxylic acid in smoked meats and bacon and that ...
Daniel F B - - 1991
Two chlorinated hydroxylated furanones, 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-furanone (MX) and 3,4-(dichloro)-5-hydroxy-2[5H]-furanone (MA), are bacterial mutagens and they are also byproducts of chlorine disinfection, and frequent contaminants of drinking water. In this work MX is shown to induce nuclear anomalies in the gastrointestinal tract of the B6C3F1 mouse. The other chlorohydroxy-furanone, MA, gives suggestive ...
Xu H X - - 1991
Capillary gas chromatography-thermal energy analysis was used for the study of volatile N-nitrosamines in comestibles. The finding of a comparatively high content of N-nitrosodimethylamine in some Chinese beers confirms the results of other authors. We describe studies of Chinese foods and environmental samples carried out in this laboratory in collaboration ...
Gao J - - 1991
Traditional uncooked and cooked Chinese foods from six provinces with different cancer patterns were analysed for volatile N-nitrosamines (VNA) by gas chromatography-thermal energy analysis. Selected samples were also analysed for N-nitrosamino acids (NAA). N-Nitrosodiethylamine was the VNA found most often (in 91/108 samples; less than 0.2-17.5 micrograms/kg), followed by N-nitrosodimethylamine ...
Walker R - - 1990
Data on occurrence of nitrate, nitrite and N-nitrosocompounds in food and drinking water, and on total dietary intakes are reviewed. Metabolic, toxicological and epidemiological studies are surveyed and the implications with respect to safety evaluation are addressed. It is concluded that, on the basis of recent long-term animal studies and ...
Connor T H - - 1990
13 lead chromate-based pigments were assayed for mutagenicity and toxicity using Salmonella typhimurium TA100. The compounds were assayed with and without S9, both in the presence and absence of the chelating agent, nitrilotriacetic acid (NTA). In general, the use of NTA to solubilize the compounds resulted in mutagenicity and/or toxicity ...
Doolittle D J - - 1990
Measuring the mutagenicity of urine is widely viewed as a means of evaluating human exposure to potentially genotoxic materials. Diet and cigarette smoking have both been reported to affect the mutagenicity of human urine, but the relationship between smoking status and the expression of diet-related urinary mutagenicity is unknown. It ...
Piasecki A - - 1990
Glycerol chlorohydrines, such as 3-chloro-1,2-propanediol and 1,3-dichloro-2-propanol, are present in commercial protein hydrolysates used for human nutrition. These compounds are genotoxic and 1,3-dichloro-2-propanol induced tumors in rats. Now it is reported that both compounds are active at inducing malignant transformation of mouse fibroblasts. Therefore, the carcinogenic risk to humans by ...
Wattenberg L W - - 1990
A continuing study of chemopreventive agents has focused on several categories of naturally occurring compounds that inhibit carcinogen activation and are effective in preventing carcinogen-induced neoplasia when administered at short time-intervals before carcinogen challenge. The inhibitory compounds are: aromatic isothiocyanates found in cruciferous vegetables, monoterpenes present in citrus fruits and ...
Skog K - - 1990
The formation of the mutagenic imidazoquinoxalines (MeIQx, DiMeIQx) was studied using a modification of a previous model system. Creatine or creatinine (0.9 mmole) was heated together with glycine (0.9 mmole) and various sugars (0.45 mmole) dissolved in diethylene glycol and water (3 ml, 5:1) for up to 15 min at ...
Sato S - - 1990
Use of hazardous environmental substances in Japan is regulated, based on their risk assessment, by laws of various ministries, depending upon the chemicals concerned. Food additives and food contaminants are controlled by the Food Sanitation Law of the Ministry of Health and Welfare. When manufacture or import of new food ...
Barrington P J - - 1990
Mutagen production was examined in lamb and beef in relation to certain common household cooking methods. Mutagenicity was assessed, after extraction of the basic fraction of cooked meat samples, using Salmonella typhimurium strain TA1538 with added rat-liver S-9 homogenate. Little or no mutagenicity was found in barbecued lamb chops, in ...
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