Search Results
Results 451 - 500 of 589
< 2 3 4 5 6 7 8 9 10 11 12 >
Miller E C - - 1986
The principal carcinogens and mutagens that have been identified in human foods are reviewed. These agents may occur in foods as naturally occurring components (e.g., metabolites made by plant or fungal cells), components of contaminating plants or microorganisms, food additives (usually unintentional), or products that arise during processing or cooking. ...
Palmer S - - 1986
Very low levels of a large variety of non-nutritive chemicals occur in the diet. Among those that occur naturally are metabolites of molds (for example, mycotoxins) and bacteria (for example, nitrosamines) and natural constituents of plants (for example, pyrrolizidine alkaloids). Many of these are occasional contaminants, whereas others are normal ...
Spirtas R - - 1986
The Chemical Substances Threshold Limit Value Committee of the American Conference of Governmental Industrial Hygienists has refined its procedures for evaluating carcinogens. Types of epidemiologic and toxicologic evidence used are reviewed and a discussion is presented on how the Committee evaluates data on carcinogenicity. Although it has not been conclusively ...
van Esch G J - - 1986
This paper traces the history of the EEC Scientific Committee for Food's examination of available toxicological data on tert-butylhydroquinone (TBHQ). Studies of mutagenicity, metabolism, enzyme activities, reproduction and long-term toxicity and carcinogenicity are reviewed. The author concludes that dose level is an important factor in the induction of forestomach tumours. ...
Powrie W D - - 1986
Heated food systems contain hundreds of chemical compounds, some being mutagenic and others being antimutagenic. Studies have indicated that foods exposed to drying, frying, roasting, baking, and broiling conditions possess net mutagenic activity as assessed by the Ames/Salmonella/microsome mutagenicity test and the chromosome aberration assay with Chinese hamster ovary (CHO) ...
Nishimura S - - 1986
From a chemical point of view, the following subjects are important areas in studies on mutagens and carcinogens in broiled foods. In addition to heterocyclic amines which need microsomal activation, the structural elucidation of more labile direct-acting mutagens is necessary. It is known that there are still various unknown minor ...
Sugimura T - - 1986
Mutation assay with Salmonella typhimurium enabled us to detect various types of mutagens in cooked foods. A series of mutagenic heterocyclic amines has been isolated and identified in broiled fish and meat and in pyrolyzates of amino acids and proteins. Feeding experiments showed these mutagens to be carcinogenic in mice ...
Nagao M - - 1986
A cup of coffee contains mutagens which produce about 5 X 10(4)-10(5) revertants of Salmonella typhimurium TA 100 without S9 mix. One of the mutagens was identified to be methylglyoxal. Methylglyoxal was present in various beverages such as black tea, whisky, and brandy. Methylglyoxal itself induced tumors in rats when ...
Weisburger J H - - 1986
Because mutagens typified by 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) observed in cooked foods are widely consumed, detailed studies of their biochemical and biological properties including carcinogenicity are most important. IQ induces unscheduled DNA synthesis in liver cells, which when taken together with its powerful mutagenicity in the Salmonella typhimurium test system, predicts carcinogenicity. ...
Rapoport H - - 1986
The imidazoquinoline and imidazoquinoxaline food mutagens found in cooked meat are being synthesized by unambiguous methods that allow for the preparation of sufficient quantities of material for biological studies. These methods avoid difficult separations of regioisomeric mixtures of products and are designed to allow incorporation of specific high level tritium ...
Krone C A - - 1986
Levels of bacterial mutagenicity 3-17 times above spontaneous are generated during commercial thermal processing (canning) of foods, particularly foods high in protein. The potential for other processing operations, including pasteurization, dehydration, and concentration, to produce substances active in the Ames Salmonella assay was also examined. Two heated fish model systems, ...
Hatch F T - - 1986
Cooking, heat processing, or pyrolysis of protein-rich foods induce the formation of a series of structurally related heterocyclic aromatic bases that have been found to be mutagens. The primary genetic assay utilized to detect and isolate these mutagens has been the his reversion assay in Salmonella typhimurium. The classification and ...
Lin G H - - 1986
FD&C Red No.3 (erythrosine) has been used as a dye in foods, drugs and cosmetics since its approval by the US Department of Agriculture in 1907. In 1977 the Certified Color Manufacturers' Association (CCMA) initiated studies on FD&C Red No.3 including chronic toxicity and carcinogenicity studies in rats and mice. ...
Goodall C M - - 1986
Low concentrations of para-nitroso-dimethylaniline (NdMA) were mutagenic to Salmonella typhimurium TA100 with optimal effect at 1.5 microM in fluctuation assays, without activating enzymes. The diethyl homologue (NdEA) had little or no mutagenic effect at low concentrations, although the bacteriocidal effects of NdMA and NdEA were similar. At higher bacteriocidal concentrations ...
Kikugawa K - - 1986
Smoked dry bonito (katsuobushi), an everyday food item for most Japanese people, was found to contain 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), the content of which was estimated at about 2 ng/g. This content is similar to the known MeIQx content of cooked beef. The katsuobushi also contained another mutagenic component, the total activity ...
Ong T M - - 1986
Chlorophyllin, the sodium and copper salt of chlorophyll, was tested for its ability to inhibit the mutagenic activity of a variety of complex mixtures--extracts of fried beef, fried shredded pork, red grape juice, red wine, cigarette smoke, tobacco snuff, chewing tobacco, airborne particles, coal dust and diesel emission particles--in strain ...
Gopalaswamy U V - - 1986
Lindane (gamma-hexachlorocyclohexane) is an important organochlorine pesticide used extensively for agricultural and public health purposes in India and in other developing countries. Because of its relative chemical stability and lipid solubility, it is known to enter food chains. This study was carried out in order to identify the metabolic capacity ...
Li M H - - 1986
Dimethylnitrosamine (NDMA), diethylnitrosamine (NDEA), methylbenzylnitrosamine, and a new N-nitroso compound, N-3-methylbutyl-N-1-methylacetonylnitrosamine (NMAMBA), were found in cornbread that was inoculated with Fusarium moniliforme and underwent an incubation and the addition of a small amount of NaNO2. The carcinogenicity of NMAMBA was shown by the induction of forestomach carcinomas and liver tumors ...
Löfroth G - - 1986
Mainstream cigarette smoke particles were collected by means of a smoking machine, and sidestream particles were collected from the room in which the smoking took place. The particles were extracted by sonication with acetone, and the extracts were solvent-exchanged to dimethyl sulfoxide. The samples were tested for mutagenicity in the ...
Knize M G - - 1985
The high-pressure liquid chromatography (HPLC) profiles of mutagenic components were compared for extracts of ground beef patties fried at 200, 250 and 300 degrees C for 6 min/side. The HPLC profiles of the mutagenic samples were similar, although total mutagenic activity in Salmonella typhimurium TA1538 was roughly four times as ...
Wakabayashi K - - 1985
After nitrite treatment, various kinds of pickled vegetables and sun-dried fishes produced in Japan showed direct-acting mutagenicity on Salmonella typhimurium TA100, inducing 1900-18000 revertants/g. Kimchis, sun-dried fishes, sun-dried squid, soy sauces, fish sauces, bean pastes and shrimp paste produced in Korea, the Philippines and Thailand also showed direct-acting mutagenicity after ...
Havery D C - - 1985
Levels of volatile N-nitrosamines were determined in 189 samples of rubber nipples for babies' bottles. Domestic (US-manufactured) and imported rubber nipples for consumer and hospital use were analysed to determine compliance with the US Food and Drug Administration's action level of 60 ppb (b = 10(9] for total volatile N-nitrosamines. ...
Hoffman C J - - 1985
Microwave-oven technology has been improved by the use of low power. With the utilization of low-power techniques, studies showed equal or better retention of nutrients for microwave, as compared with conventional, reheated foods for thiamin, riboflavin, pyridoxine, folacin, and ascorbic acid. Beef roasts microwaved at "simmer" were comparable with conventionally ...
Hayatsu H - - 1985
Fried ground beef has been shown to contain mutagens, and the major mutagenic component has been identified as 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx). Mutagens in feces of 3 adult volunteers were fractionated by treatment of the feces with blue cotton followed by chromatography on a carboxymethyl cellulose column. The chromatographic fraction, corresponding to ...
Fiddler W - - 1985
Laboratory personnel of Eastern Regional Research Center, USDA, are required to wear disposable latex or vinyl gloves for certain analyses involving nitrosamines. In order to assess possible exposure of the wearers of these gloves, a limited survey was carried out on the volatile nitrosamine content in disposable protective gloves. Six ...
Pintauro S J - - 1985
Lysinoalanine (N epsilon-(DL-2-amino-2-carboxyethyl)-L-lysine) was tested for mutagenicity in the Ames Salmonella/mammalian-microsome mutagenicity assay. No mutagenic response was detected at doses up to 5 mg/plate when samples were pre-incubated without S-9 mix, nor when they were pre-incubated with S-9 mix prepared from Aroclor 1254-induced rat liver or kidney. The results indicate ...
Shimada H - - 1985
When a mixture of N-nitrosomorpholine and S. typhimurium TA100 in saline was irradiated with near-ultraviolet light, mutagenesis of the bacteria took place. The same observation was made with S. typhimurium TA1535, E. coli WP2 uvrA, pKM101 and uvrA/pKM101. Several other nitrosamines showed ed the same, but weaker, effect. Evidence is ...
Fritsch P - - 1985
The kinetics of salivary and biliary excretion of inorganic nitrates and nitrites was studied in mongrel dogs after iv injection of these compounds labelled with 15N. There was strong salivary excretion of 15NO-3 after injection of Na15NO3 but little or no nitrites were excreted in the saliva, indicating that the ...
Albertini S - - 1985
Mutagenic products can be formed during the processing of food and especially as a result of heat treatment. Direct acting mutagenic activity was found in extracts of instant coffee and roasted coffee beans using Salmonella typhimurium TA100 in vitro. The mutagenic activities of the four pure coffee varieties examined (Coffea ...
Jouany J M - - 1985
Thiram, a dithiocarbamate fungicide, is known to evolve to dimethylnitrosamine (DMNA) when associated with nitrites. Conditions of appearance of that carcinogenic compound have been studied in short-term experiments by association of the fungicide, nitrates or nitrites, and species representative of freshwater biota. DMNA has been estimated by GLC equipped with ...
Tannenbaum S R - - 1985
The hypothesis linking nitrate and increased risk of cancer rests on the proposition that nitrate is endogenously reduced to nitrite by bacteria and that carcinogenic N-nitroso compounds are formed. A large number of foods and biological material have been examined for their ability to generate mutagens or carcinogens under simulated ...
Nagao M - - 1985
Nitrosatable precursors of mutagens that show mutagenicity to Salmonella typhimurium TA100 without S9 mix after treatment with nitrite at pH 3 were found in various foods. From Chinese cabbage, three indole compounds, indole-3-acetonitrile, 4-methoxyindole-3-acetonitrile, and 4-methoxyindole-3-aldehyde, were identified as mutagen precursors. 1-Methylindole and 2-methylindole, which are present in cigarette smoke ...
Ohnishi Y - - 1985
Identification of mutagenic factors in foods is of concern because they may represent carcinogens to man. Cooked foods, especially their basic fractions containing heterocyclic amines, have high mutagenicity; the neutral fractions containing mutagenic nitropyrenes, however, have not been studied in detail. The mutagenicity of various grilled foods--10 vegetables, 4 fish, ...
Watson D H - - 1985
Interest has increased recently in the possible human carcinogenic effects of plant metabolites in the diet. Some psoralens, some pyrrolizidine alkaloids and 'bracken carcinogen' may be dietary carcinogens, the latter two via contamination of food products from animals ingesting toxic plants. With the exception of 'bracken carcinogen', the structures of ...
Anderson D - - 1985
In vitro testing of food products for mutagenic activity presents particular problems, especially in connection with the administration of the test material to the assay system, the possible interference of food components with the genetic end-point used for the assay, the presence in foods of various factors that may modify ...
Flamm W G - - 1985
Beryllium-containing compounds have been studied extensively and have been known to be carcinogenic in animals since 1946. Beryllium salts and alloys were among the first nonradioactive, inorganic substances shown to induce osteogenic sarcoma in experimental animals. Beryllium-containing compounds have been demonstrated to be powerful pulmonary carcinogens in rats. To date, ...
Tóth K - - 1984
Previous studies have indicated that both herbicide 2,4,5-trichlorophenoxyethanol (TCPE) and its contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) enhance liver tumor incidence in male Swiss mice in a dose-dependent manner. In this report the mutagenicity of TCPE (containing 0.1 p.p.m. TCDD) in the Salmonella/microsome assay was studied, and the effect of this herbicide on ...
Krone C A - - 1984
Mutagens are shown to be present in a variety of commercially heat-processed foods. Since these substances are not present in the unheated raw material, it appears that they are produced during processing. Canned salmon and beef broth showed the highest mutagenicity while other canned beef and fish products yielded lower ...
Lasne C - - 1984
The sensitivity of a cytogenetic assay, as expressed by the in vitro induction of micronuclei (MN), was compared to the in vitro induction of sister-chromatid exchanges (SCEs). Chinese hamster lung (V79) cells were exposed to 3 known alkylating agents: methyl methanesulphonate (MMS), ethyl methanesulphonate (EMS) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and to ...
Ji C - - 1984
A new N-nitroso compound, N-2-methylpropyl-N-1-methylacetonyl-nitrosamine (MAMPNA), was found in millet and wheat flour inoculated with Fusarium moniliforme Sheldon, a common species of fungi occurring in foods in Linxian County, after 8-day incubation and an addition of a small amount of NaNO2. The compound has been identified by GC-MS and confirmed ...
Minkler J L - - 1984
Sister-chromatid exchange and chromosomal aberrations were measured in vivo in mouse bone marrow following intraperitoneal injection of the cooked food mutagens, Trp-P-2 and IQ. Trp-P-2 produced a significant positive dose response for both endpoints while IQ produced only a weak but significant sister-chromatid exchange response. The relative potency of these ...
Lüthy J - - 1984
N-nitrosamides are known as direct-acting carcinogens at the site of their formation; they do not need any metabolic activation in vivo. The conditions leading to their formation in the stomach, and also their genotoxicity, have been thoroughly studied with some model compounds. Several reports link this type of compound to ...
Bos R P - - 1984
In a small wood preserving industry spot samples were taken from contaminated surfaces at several places and tested for mutagenicity. The results suggest that the application of a wipe test can give a first indication of occupational exposure to mutagenic and carcinogenic substances, particularly when exposure occurs more from skin ...
Wislocki P G - - 1984
The potential toxicity of ronidazole residues present in the tissues of food-producing animals was assessed using the Ames mutagenicity test. Since ronidazole is activated by reduction, reduced derivatives of ronidazole and metabolites formed by enzymatic reduction of ronidazole were tested for mutagenicity. When tested at levels several orders of magnitude ...
Overvik E - - 1984
Lean pork was pan-broiled at various temperatures between 100 and 290 degrees C. Cooking was performed in an open frying pan common for domestic use in Sweden. No fat was added. Cooking procedures are clearly defined in order to facilitate inter-laboratory comparisons. The crust was extracted with organic solvents of ...
Massey R C - - 1984
The apparent total N-nitroso content of foods can be measured by a procedure based on chemical denitrosation and chemiluminescent detection of the eliminated nitric oxide. Procedures have been established which substantially reduce the 'apparatus blank' response to the denitrosating agent and allow total nitroso contents down to 10 micrograms (N-NO)/kg ...
Hotchkiss J H - - 1984
It has been well established that human foods may contain trace amounts of carcinogenic N-nitrosamines. Originally, it was thought that the use of nitrite as a curing agent for flesh foods was the major source of these trace compounds in the diet. Subsequent research has clearly shown that other processing ...
Friedman M - - 1984
Oxygen, oxidizing enzymes such as polyphenol oxidase (tyrosinase) and alkaline pH, irreversibly inactivate the mutagenicity of quercetin in the Ames test. The loss of mutagenic activity correlates with decreases in the ultraviolet absorption maximum of quercetin near 370 nm. The extent of inactivation increases with time but apparently not significantly ...
Montes G - - 1984
In a search for possible sources of mutagens in human foods, a study was made of six common foods in the diet of a population at high risk for gastric cancer (in Nariño, Colombia). No mutagenic activity was demonstrated in nonnitrosated foods. After nitrosation, only one of the foods, fava ...
Croisy A - - 1984
Bis-methylthio-diiron-tetranitrosyl (Roussin's red methyl ester, RRME), recently identified in pickled vegetables consumed in a high incidence area of oesophageal cancer in Northern China, was examined for its activity as a nitrosating agent in vivo and in vitro. Freshly synthesized RRME nitrosated secondary amines (morpholine and pyrrolidine) slowly in the presence ...
< 2 3 4 5 6 7 8 9 10 11 12 >