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B Pignatelli

Publications and source records attributed to B Pignatelli.

63 records · Page 4Linked to original sources
PubMed1976

Effects of gallic acid and of ethanol on formation of nitrosodiethylamine.

In vitro experiments demonstrate that the polyphenol, gallic acid, can both catalyse and inhibit NDEA formation. The products of reaction depend considerably on pH conditions and relative concentrations of the reactants. Therefore, interpretation of in vitro experiments in terms of possible in vivo effects in a given population must take into consideration detailed information on eating and drinking habits which might affect pH conditions and relative concentrations of the reactants in the digestive tract. In this respect, it is interesting to note that epidemiological studies conducted by the agency (Day 1) indicate that tea, which contains gallotannins, is consumed more frequently but in a more diluted brew in the area of high oesophageal cancer incidence of the Caspian littoral than in the low incidence area. Our preliminary study on ethanol suggests that its effects will be found to lack the complications present with the tannins and would thus be more easily extrapolated to in vivo situations.

Catalysis↗
PubMedDate not supplied

In vivo nitrosoproline formation and other risk factors in Costa Rican children from high- and low-risk areas for gastric cancer.

The hypothesis that intragastric synthesis of N-nitroso compounds (NOC) in early life could play a role in gastric carcinogenesis was tested by applying the N-nitrosoproline (NPRO) test to about 50 children living in high- and low-risk areas for stomach cancer in Costa Rica. The median values of excretion of NPRO and the sum of three nitrosamino acids (micrograms/12 h urine) were 10-20% of those in adults from other geographical high-risk areas for stomach cancer. The urinary NPRO level after proline intake was higher in children from the high-risk area (P < 0.04) and markedly reduced after ingestion of ascorbic acid together with proline (P < 0.05). NPRO levels on the day of proline intake were highly correlated with levels of nitrate excretion (P < 0.001). Mean levels of total NOC in an aqueous (pH 2) extract of cooked beans from the high- and low-risk areas were similar. Acid-catalyzed nitrosation of the extract increased the total NOC concentration up to 1000-fold, but there was no difference between samples from the two areas. About 10% of bean extracts from both areas showed weak direct-acting genotoxicity in Escherichia coli; after acid-catalyzed nitrosation, all samples were genotoxic at similar levels. The diet of children in the low-risk area satisfied recommended levels of intake of energy and most nutrients except riboflavin and retinol equivalents. Diets from the high-risk area were deficient in energy intake and all nutrients except protein and vitamin C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗