PubMed Health⌕ Search

Biomedical subjects

A E Wasserman

Publications and source records attributed to A E Wasserman.

18 recordsLinked to original sources
PubMed1982

Nitrosamine levels in human blood, urine and gastric aspirate following ingestion of foods containing potential nitrosamine precursors or preformed nitrosamines.

In studies of the effect of diet on nitrosamine levels in selected human physiological fluids, volunteers were fed meals containing fish or beef (sources of precursor amines) or bacon (a source of preformed nitrosamines), in combination with spinach and vegetable juice to supply nitrite via possible reduction of nitrate. Blood, urine and gastric contents were sampled periodically for up to 4 hr after feeding. The results of the study indicated that traces of nitrosamines, usually N-nitrosodimethylamine, were present in many samples of blood, urine and gastric contents, even after an 8-hr fast. Eating the test meals led to a slight increase in nitrosamine levels in the blood and stomach contents in a few subjects. The data obtained from this study suggest that gastric formation of nitrosamine does not appear to be an important health factor in normal people, since the levels of nitrosamines found in physiological fluids are not markedly increased after eating.

Adult↗
PubMed1981

Interaction between sample preparation techniques and colorimetric reagents in nitrite analysis in meat.

The amount of nitrite measured in model and meat systems was a function of the interactions of the chloride and ascorbate concentrations with the method of sample preparation and the combination of Griess reagents used for colorimetric determination. Ascorbate caused loss of nitrite in the samples when heated and interfered in the Griess reaction, increasing the concentration of pigment formed from any given concentration of nitrite if sulfanilic acid and N-(1-naphthyl)-ethylenediamine were used, and decreasing the amount if sulfanilamide and 1-naphthylamine were used. The interference was eliminated by both the AOAC procedure and mercuric chloride addition, although the former were less effective at higher ascorbate concentrations. Chloride increased the amount of pigment formed from a given amount of nitrite with sulfanilic acid but had no effect on the amount of sulfanilamide pigment.

Ascorbic Acid↗
PubMed1978

Preliminary observations on amines and nitrosamines in non-normal human gastric contents.

Gastric contents from fasting humans were pooled and analysed for amines. Volatile amines present were dimethylamine, trimethylamine and histamine; non-volatile amines found were cadaverine, putrescine, ethanolamine and tryptamine. Gastric contents from 35 patients, some before and/or after gastric stimulation with histamine or pentagastrin, were analysed for nitrosamines. N-Nitrosodiethylamine (NDEA) (5-30 microgram/kg) was present in four samples, N-nitrosodimethylamine (NDMA) (2 microgram/kg) in two samples and N-nitrosopyrrolidine (NPYR) (6 microgram/kg) in one sample. pH, nitrite and nitrate determinations were made on some samples. Medical diagnosis of patients could not be correlated with the presence of nitrosamines in the gastric contents.

Amines↗
PubMed1977

Inhibition of Clostridium botulinum by 5-nitrothiazoles.

A number of 5-nitrothiazoles with various substituents in the 2-position were tested for inhibition of Clostridium botulinum in a culture medium. Thiazole itself or 2-bromo- or 2-methylthiazole at 30 mug/ml did not inhibit the organism. An amino group in the 2-position of thiazole inhibited at 10 mug/ml. Substitution of a nitro group in the 5-position of 2-aminothiazole increased the inhibitory level to 0.12 mug/ml; acetyl-, propionyl-, or butyroyl-2-amino-5-nitrothiazole inhibited at 0.04 mug/ml. Benzoyl-2-amino-5-nitrothiazole inhibited at 0.16 mug/ml; this increased to 0.01 mug/ml when the benzoyl group carried a nitro group in the m- or p-position; a nitro group in the o-position, on the other hand, inhibited at 0.04 mug/ml. Unsaturated aliphatic acyls decreased inhibition. The greatest activity was exhibited by 2-nonanoyl- and 2-lauroylamides, with minimum inhibitory concentrations of 0.005 and 0.0025 mug/ml, respectively.

Chemical Phenomena↗