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Biomedical subjects

J Kann

Publications and source records attributed to J Kann.

At least 37 records · Page 2Linked to original sources
PubMed1982

Research on environmental N-nitroso compounds in the USSR.

Food samples from various parts of the USSR have been analysed for volatile N-nitrosamines (NA). The results are comparable to data published elsewhere. Kilning of malt with direct combustion gases accounts for the presence of NA in beer. NA have been found in city air, diesel exhausts and in a rubber factory. Vulcanized rubber contains NDMA and NMOR. Nitrosoproline has been determined in a variety of foodstuffs. Variations of nitrate contents in vegetables due to mineral fertilizers and some herbicides are reported. A steady increase of average nitrate concentrations in vegetables has been observed in Estonia over a period of 12 years. Precursors of NA have been found in water (Moldavia), and soil (Moscow district and Tshuvash republic). Nitramines can be formed in vivo from NA, and vice versa. Formation of NDMA from aminopyrine has been inhibited under gastric conditions by properly composed meals. Numerous food components have been studied as nitrite scavengers. Modifications of analytical methods for NA have been proposed. Four laboratories in the USSR are equipped with the Thermal Energy Analyzer.

Air Pollutants↗
PubMed1979

Carcinogenic N-nitrosodimethylamine as a contamination in drugs containing 4-dimethylamino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (amidopyrine, aminophenazone).

A total of 68 commercially available drugs containing amidopyrine were investigated for contamination with the strong carcinogen N-nitrosodimethylamine (NDMA). All samples contained varying amounts of NDMA. About half of the drugs contained 1--10 micrograms/kg, 40% contained 11--50 micrograms/kg, 7% contained 51--10 micrograms/kg and one sample had 370 micrograms/kg. NDMA-contents in batches of pure amidopyrine that had been utilized for preparation of drugs were higher than those in the respective drugs: about one-third was in the range of 20--50 micrograms/kg, one-third had 51--100 micrograms/kg, and one-third was above 100 micrograms/kg. There was, however, no correlation between NDMA-contents of batches of the pure substance and NDMA-contents of the drugs prepared from these batched. NDMA concentrations in the samples were inhomogenously distributed. It could be demonstrated that amidopyrine in substance reacts extremely rapidly with nitrogen oxides from the air to form NDMA. Ascorbic acid, which prevents nitrosamine formation in aqueous-acidic solution, under these conditions had no protective effect.

Aminopyrine↗
PubMed1978

Volatile and non-volatile N-nitroso compounds in foods and other environmental media.

A further series of cured meat products (meat loaf, liver loaf, bologna) has been investigated for their nitrosamine contents before and after frying. Contents in general were in the low microgram/kg range. An extensive study of nitrosamine contents of various types of cheese has been terminated. Although 45% of all samples showed indications of nitrosamine content, only 12% had concentrations of greater than 1 microgram/kg (1-6 microgram/kg); NDMA was more often found in hard and in soft cheese, than in other types. Analytical grade dichloromethane and chloroform have been found to contain N-nitrosomorpholine in concentrations of 2-376 microgram/kg (27-40% of the samples). The origin of the contamination is not known at present. A survey of the nitrosamine content of animal diets showed that 80% of all samples had contents of greater than 1 microgram/kg. NDMA (up to 79 microgram/kg) and NPYR (up to 26 microgram/kg) were most often found. There are indications that fish meal is the main source of contamination. Drugs containing amidopyrine (AP) have invariably been found to contain NDMA. Concentrations varied within wide limits (less than 10 microgram/kg - 371 microgram/kg). No correlation has been found between samples of pure AP and NDMA contents of drugs in which pure AP had been incorporated. Also, strong variations in NDMA contents have been found within individual batches, probably caused by the high reactivity of AP towards nitrogen oxides. The determination of N-nitroso-3-hydroxypyrrolidine has been further improved and a further series of food analyses for contents of this nitrosamine has been carried out. About 30% of the samples were positive with contents below or near 10 microgram/kg. An analytical method for determination of N-nitrosamino acids has been worked out. The method consists of a series of extraction, liquid/liquid distribution and chromatography steps; N-nitrosoamino acids are finally determined, after trimethylsilylation, with a TEA detector. First results on the occurrence of these compounds in various cured meat products are reported.

Animal Feed↗
PubMed1977

Occurrence of volatile N-nitrosamines in animal diets.

46 samples of commercially available diets for experimental animals have been analysed for their content of volatile N-nitrosamines by use of a nitrosamine-specific detection method (TEA-detector). 80% of all analysed samples were positive for N-nitrosodimethylamine with a maximum content of 79 ppb (microgram/kg) found in one sample. 59% of the samples were positive for N-nitrosopyrrolidine with 26 ppb as highest content. In 3 samples trace quantities (less than 1 ppb) of N-nitrosodiethylamine were found, one sample contained N-nitrosopiperidine (4 ppb).

Animal Feed↗